Last Updated on August 22, 2018 by Patricia Carter
SUMMARY (updated Aug 2018): Dr. Rob Knight’s talk, Saturday, October 18, 2014, listed eleven factors that optimize the gut microbiome based on the American Gut Data cautioning all is preliminary. These are listed below along with an interesting article titled: “Can We Eat Our Way To A Healthier Microbiome? It’s Complicated,” in which Dr. Knight and Jeff Leach (founders of crowd sourcing project “American Gut”) discuss the microbiome diet. A KEY finding was that the more vegs consumed (30 different each week is BEST), the more diverse the microbiome, and that is thought to be associated with health and improved immune status since MANY chronic diseases (see the below Table) have changes in microbiome diversity AND composition, [Cantinean et al 2018]. A 2018 update on the American Gut data just published, [McDonald et al 2018], and it still says to eat 30 different vegs each week! This post also provides insight into what the microbiome experts are saying about translation of microbiome research into clinical practice. And last, my synopsis of Dr. Knight’s talk is provided (see below the light bulb) along with my listing of fav microbiome researcher labs whose work is discussed in this post! Use them and PUBMED for your own disease prevention or mitigation research. Always. Stick with the evidence for answers as this blog does.
Microbiome and associated health problems
![[Catinean et al 2018] Figure 1, Microbiome and associated health problems](https://i0.wp.com/biomeonboardawareness.com/wp-content/uploads/2014/10/Catinean-et-al-2018Microbiome-and-associated-health-problems.png)
| Disease | Changes in microbiota’s diversity and composition | Consequences | Reference |
|---|---|---|---|
| Inflammatory bowel disease | Less bacterial diversity ↓ the number of Bacteroides and Firmicutes | decreasing the concentration of butyrate | Lucas López et al. (2017) |
| Irritable bowel syndrome—diarrhea | ↑Enterobacteriaceae↓Faecalibacterium prausnitzii | not known | Dupont (2014) |
| Constipation | ↑Firmicutes(Lachnospiraceae and Ruminococcaceae)↓Bacteroidetes (Prevotella) | increasing the production of butyrate | Zhu et al. (2014) |
| Obesity | Changes in the ratio of Bacteroidetes/Firmicutes↓ the abundance Akkermansia muciniphila↑ the abundance Campylobacter, Shigella, Prevotella | decreasing the production of butyrate | Festi et al. (2014),Tremaroli & Bäckhed (2012) |
| Diabetes T2 | ↓Bifidobacterium spp significant association of Parabacteroides with diabetic patients | not known | Wu et al. (2010) |
| ↓Firmicutes↑Bacteroidetes, Proteobacteria | it is possible to determine endotoxemia → oxidative stress → IL1, IL6, TNF α | Marlene (2013) | |
| Diabetes T1 | ↓Lactobacillus, Bifidobacterium, Blautia coccoides–Eubacterium rectale, Prevotella | decreasing the production of butyrate decreasing the synthesis of mucin increasing the intestinal permeability | Murri et al. (2013) |
| ↓Clostidium clusters IV and XIV (species that produce butyrate) | decreasing the production of butyrate | De Goffau et al. (2014) | |
| Dyslipidemia | ↓Lactobacillus | decreasing enzymatic deconjugation of bile acids → increasing the level of cholesterol | Kumar et al. (2012), Ramakrishna (2013) |
| Nonalcoholic steatohepatitis | ↓Firmicutes↓Faecalibacterium and Anaerosporobacter (order Clostridiales)↑Parabacteroides and Allisonella (order Aeromonadales) | increase in luminal gut ethanol production metabolism of dietary choline release of lipopolysaccharides increasing small intestinal bacterial overgrowth increasing endotoxemia increasing lipopolysaccharide →↑ insulin resistance and ↑ TNF alpha | Compare et al. (2012), Wong et al. (2013) and Machado & Cortez-Pinto (2012) |
| Acute coronary syndromes | not know | trimethylamine is formed by gut microbiota from nutrients which contain l-carnitine, choline, phosphatidylcholine followed by the formation of trimethylamine N-oxide (TMAO) by hepatic enzymes increasing the plasmatic level of TMAO–increasing the risk of myocardial infarction and stroke | Trøseid (2017) |
| Autistic spectrum disorders | ↑Clostridium histolyticum (Clostridium clusters I and II)↑Bacteroidetes, Desulfovibrio↓Firmicutes | increasing the production of neurotoxins | Parracho et al. (2005), De Angelis et al. (2013) |
| Allergy | ↑Lactobacillus, Enterococcus | increasing of allergic sensitization | Kirjavainen et al. (2002) |
| low diversity of microbiota ↑Bacteroidales↓Clostridiales | not know | Hua et al. (2016) |
Dr. Rob Knight’s eleven point punch list of things that seem to be beneficial to the microbiome are:
- Eat lots of plants: 5 to 30 different varieties each week preferably. This finding is so profound that “American Gut” will soon change participant food journal requirements to “only ask for frequency on consumption of holistic food within the past month, instead of the three week food journal. This change is warranted since the long term diet, especially meat and fiber consumption, has been shown to have the largest effect on the microbiome.”
- Aging increases microbiome diversity: Microbiomes are more diverse at age 50 to 60 then populations in their twenties (see above slides).
- Having an IBD diagnosis means your microbiome is altered. NOTE: Many chronic and autoimmune diseases are also following suit.
- The time of year alters the microbiome with a more diverse microbiome being with sun and outdoor exposure.
- Antibiotics wipe the microbiome with some folks recovering relatively soon whereas others do not recover the pre-antibiotic microbiome even one year later.
- Males vs females: The sex for a given microbiome can now be accurately predicted.
- Sleep 8 hours for a more diverse microbiome. Less than 6 hours yields a less diverse microbiome.
- BMI but it only subtly affects the microbiome.
- Plants: eating 6 to 10 each week is good, but eating 30 plus different varieties is best. (See further discussion below.)
- Alcohol: one drink is helpful, more than one reduces diversity.
- Frequent exercisers have a more diverse microbiome and it is best if exercise is outdoors rather than indoors.
What’s up with plants and the microbiome?
Here is a great read where Dr. Knight and Jeff Leach talk about plants (and their fiber): Can We Eat Our Way To A Healthier Microbiome? It’s Complicated. In sum, “eating too little fiber could starve the bacteria we want around. “When we starve our bacteria they eat us,” Leach says. “They eat the mucus lining – the mucin in our large intestine.” Knight adds that when we do keep our bacteria well fed, they, in turn, give off nutrients that nourish the cells that line our guts. Fiber, Knight says, “is thought to be good for your gut health over all.” You can read the post, Fiber Additives Starve Gut Microbes. They Eat Mucus Lining for more on all that! Bottom line: Harness this information to positively nudge your microbiome towards health. Note too that everyone is uniquely different so the right diet depends a lot on the individual’s lifestyle AND that individual’s microbes. More tips from the article are:
- There are a lot of different ways to get fiber. Leach recommends getting it from vegetables. Eat a variety of veggies, and eat the whole thing, he recommends. “If you’re going to eat asparagus, eat the whole plant, not just the tips,” he says.
- Fiber was also central to Leach’s suggestion to Stein to eat more garlic and leek. Those vegetables contain high levels of a type of fiber called inulin, which feeds actinobacteria in our guts. In fact, inulin is considered a prebiotic, since it feeds the good bacteria, or probiotics, that live inside us.
- Garlic actually has antimicrobial properties, which paradoxically, could also be good thing for our microbiomes. One study shows that garlic hurts some of the bad bacteria in our guts while leaving the good guys intact. [Filocamo et al 2012]
- Eat fermented foods which contain probiotics along with foods that feed those probiotics. Fermented foods like kimchi, sauerkraut and yogurt might be surer sources of probiotics. Researchers are unclear about whether these have any lasting effect on the composition of our microbiome, but in some cases they do seem to help. “Epidemiologically there seems to be some evidence that eating fermented food is beneficial rather than harmful,” Knight says. But researchers are still trying to figure out why.
⇒ A key benefit of fiber beyond regularity, is that when the microbiome ferments it, short chain fatty acids (SCFAs) are produced.
This study, from Nutrition & Diabetes, summarizes SCFA nicely: “Colonic fermentation is a complex process that occurs through the interactions of many microbial species and involves the anaerobic breakdown of dietary fibre, protein and peptides.1, 2, 3 The principal end products of colonic fermentation are the short chain fatty acids (SCFAs) acetate, propionate and butyrate, the gases hydrogen, carbon dioxide and methane4, 5, 6 and energy, which is used by the microbiota for growth and maintenance of cellular functions.7 Small amounts of branched chain fatty acids (iso-butyrate, valerate and iso-valerate) are also formed from protein and amino acid degradation. The amount and type of dietary fibre are among the major determinants of gut microbial composition and SCFA production patterns.8 In humans, the SCFA produced account for 5–10% of total dietary energy.9 ) [Fernandes et al 2014]
However, we have a lot yet to learn regarding SCFA:
[Fernandes et al 2014] notes that for overweight and obese participants, SCFAs were increased. This is contradictory of the current thinking that increased fiber results in decreased risk of obesity. In sum, researchers believe the obese microbiome SCFA differences reflect a microbiome that harvests more energy from the diet. Key points are:
- “Dietary intake is a key factor in the pathophysiology of obesity, and habitual dietary intakes also have a role in determining gut microbiota composition.38, 39,40, 41, 42 No significant differences in dietary intakes between the two groups in this study were observed. Interestingly, TDF intakes were similar in the two groups even though the OWOB group had significantly higher faecal SCFA concentrations and this may imply that colonic fermentation in the obese microbiome is more efficient. It is also possible that there might have been some under reporting of dietary intakes in the OWOB group. Faecal SCFA were inversely related to the intake of TDF per 1000 kcals in LN but not in OWOB participants, which may suggest that the lean microbiome may ferment dietary fibre differently from the obese microbiome. The inverse association may also suggest that LN participants may absorb more SCFA or that there might be bacteria associated with the lean microbiome that may breakdown SCFA in order to utilize it as an energy source.
- Negative correlations were also observed between PUFA intakes and various microbial phyla. Most of the genes present in the gut microbiome do not generally engage in fatty acid breakdown.43 However, studies have shown that PUFA significantly alters colonic fermentation.44, 45 In vitro studies have shown a modulatory effect of PUFA concentrations on the growth and adhesion of different Lactobacillus strains.46 In rats, a decrease in the number of Bacteroides fragilis species and total anaerobes in the caecum was observed after fish oil consumption, which is rich in long chain n-3 PUFA.47Dietary fatty acids may alter the fatty acid composition of the intestinal wall and modify the attachment site to promote or inhibit microbial colonization.
There’s KEY things beyond fiber that those 5 to 30 different varieties of plants each week gives us!!!
The benefits of eating many diverse plants is as expected from general guidelines to date and it includes lots of leafy greens and brightly colored vegetables which also contains carotenoids, anthocyanins, lycopenoids, and other beneficial plant compounds, which also change up the microbiome in healthful directions:
![[Catinean et al 2018] Figure 1 Gut microbiota and associated health problems](https://i0.wp.com/biomeonboardawareness.com/wp-content/uploads/2014/10/Catinean-et-al-2018Microbiome-and-associated-health-problems.Fig-2.png?fit=300%2C236&ssl=1)
Lastly, microbiome diversity is increased by eating more variety of plants. A diverse microbiome is a healthier host!
It is thought that greater diversity means improved immunity since many diseases (including obesity, diabetes, colon cancer and IBD…) are associated with reduced microbiome diversity and altered composition. Figure 1 AND Table 1 above from [Cantinean et al 2018] showed MANY chronic disease associations with microbiome problems. The ratio of plant to animal foods (a.k.a. the ratio of carbohydrates to protein) significantly affects the microbiome and is complex. Researchers are only now beginning to study individual foods and are learning that they vary in metabolites based on where they are grown, how they are stored, and even how they are cooked.
[Yatsunenko et al 2012] links meat to pro-inflammatory differences in the gut microbiome composition when compared to diets that heavily rely on plant foods as does [David et al 2013]. See my CME slides:
And there are studies showing adverse healthy consequences associated with meat consumption such as [Koeth et al 2013], which found that gut microbes metabolize L-carnitine found in red meat into TMAO, and that can lead to hardening of the arteries⇒ atherosclerosis. In mice, a compound named DMB, found in EVOO, balsamic vinegar, grapeseed oil, and red wine, mitigated that. Relevant CME slides are:
That said, there are certain diseases that modified plant/meat ratios seem to benefit such as IBS (where FODMAPS help), or gluten and casein free (or GAPS) for autism, SCD for IBD, Wahl’s diet for MS, a temporary ketogenic type diet for Type 2 Diabetes or Metabolic Syndrome, a ketogenic diet for epileptic seizures…).
WHAT MICROBIOME EXPERTS ARE SAYING ABOUT TRANSLATING HUMAN MICROBIOME RESEARCH INTO CLINICAL PRACTICE!
[Slashinski 2014] Investigators’ Perspectives on Translating Human Microbiome Research into Clinical Practice looked at 60 in-depth, semi-structured interviews (2009-2010) with 63 researchers and National Institutes of Health project leaders (‘investigators’) involved with human microbiome research. The interviews explored a range of ethical, legal and social implications of human microbiome research, including investigators’ perspectives on potential strategies for translating findings to clinical practice. The conclusions:
• We need to consider embracing a new paradigm of health and
disease, further delineate the importance of microbial communities and pursue the potential clinical utility of this research,
• We should consider avoiding the use of rhetorical devices used to construct bacteria as invaders, not co-habitants, of the human body (i.e. ‘germ warfare,’‘sterilizing our exterior,’ etc), and
• [This research] will yield ‘multiple applications that will be quite relevant to science and medicine’ (investigator 101), ‘fundamentally shift[ing] medicine and medical treatment’ (investigator 140) and [will] revolutionize medicine, clinical
practice and ‘how we treat human health’ (investigator 162).
My synopsis of Dr. Knight’s talk (email me for a more detailed PDF copy):
It is crucial to understand that researchers are just starting to find out about the profound effects of the microbiome on health and disease. Much progress has been made in the last 5 years, but many compelling questions remain unanswered. It is the recent gene sequencing technological advances that has launched new studies that are revolutionary in how we view biology. Publications of studies based on this technology only broke out in the scientific literature in 2011 and 2012 and are aimed at understanding how (and, more importantly, why) humans harbor multitudes of symbiotic bacteria. Up until now, we never knew that microbes are so involved with the process of sustaining our life as researchers now catalog microbes they’ve never before seen: they have no scientific name; they are not culture-able; they are only “seen” though DNA sequencing.
For Background: The human body is permanently colonized by microbial organisms on virtually all environmentally exposed surfaces: skin, mouth, respiratory, genitalia , and the largest colonizer, the gut.
In the GI tract, microbes outnumber host cells by 10-fold. We have 10 trillion human cells, but 100 trillium microbial cells. Thus, we are 90% bacteria, or 10% human, on a cellular level. On a gene level, we have only 20,000 human genes. But, our microbial genes, range from 2 to 20 million; we carry around mostly microbial genes! –Dr. Rob Knight, “How microbes could cure disease: Rob Knight at TED2014”
“It is precisely due to our microbiome, and the micobiota that it contains, that we are able to even live as they give us all the genes and proteins our human genome does not encode.”
“You can think of it as: humans are actually the bystanders; it is the microbiota that does all of the work.”
~‘Animated Life: Seeing the Invisible’
In general, humans have very similar DNA, but our microbiome’s differ tremendously. Additionally, each of our externally exposed microbiome regions differs from one another which makes sense since the microbiome preforms different functions for different parts of our body. What was more amazing, was that our individual microbiome regions are virtually changing. Only in 2012 did we learn that the vaginal microbiome alters throughout pregnancy ultimately becoming much less diverse and increasing tremendously in certain specific bacterial species: [Koren et al 2013]1 showed increases in Proteobacteria (usually associated with inflammation) and increases in Actinobacteria species (more common in metabolic syndrome [Woting et al 2016] [Vijay-Kumar et al 2010] 2 ), and the study [Aagaard et al 2012] showed Lactobacillus species (prevents the growth of harmful bacteria and aids human digestion) increased, despite the newborn microbiota (inoculation during vaginal delivery) resembling the mother’s first trimester vaginal microbiome (which isn’t that much different from non-pregnant). If interested, see reference 6 below for further discussion. Additionally, you can read this post, “Microbiome, What Disrupts It?” and this post, “Microbiome Rules, What Is It?” to better understand some of the factors that determines, disrupts, and alters the microbiome communities.
THE ROLE OF THE MICROBIOME
Many vital host functions are provided by the microbiota including the synthesis of vitamins and antibiotics that we can not currently commercially manufacture, digestion of complex polysaccharides, maintenance of the intestinal epithelial barrier, and resistance to pathogen colonization. “It is precisely due to our microbiome, and the micobiota that it contains, that we are able to even live as they give us all the genes and proteins our human genome does not encode. You can think of it as: humans are actually the bystanders; it is the microbiota that does all of the work.” ~‘Animated Life: Seeing the Invisible’
Millions of years of co-evolution have inextricably linked the health of mammals to their microbiota. We have a lot of catch up using gene sequencing technology since not a lot of what was seen under the microscope was ever culture-able. Estimates range from only 0.1% to 1% of that seen microscopically is culture-able, or that 99% is not culture-able! And that which is culture-able may not even be the most abundant nor may it be very important. This is now called “The Great Plate Anomaly.” An example of a major game changer: for decades we easily grew e-coli in a culture dish with medium thinking, since it grew so well, it was a predominant player in our gut. Well, truth now be told, e-coli is only one cell in a million in a healthy gut. Realize this significance: your doctor’s throat culture can’t detect 99% of the bacteria present for diagnosis perhaps giving new meaning to the term “broad spectrum antibiotic.”
Another game changer for microbiome research involves keeping the DNA alive.
DNA sequencing now looks at dead DNA. The microbiome is anaerobic thus, new devices (see below slides), techniques and growing mediums that remove oxygen and keep the DNA alive are being used to gather data. Future application of this technology will allow input of probiotics, or soil fertilizers… and researchers will be able to see in real time, microbiome effects. Another brilliant researcher evaluating the fermenting real time gut microbiome would be Dr. Emma Allen-Vercoe who presented at the 1st International Symposium on the Microbiome in Health and Disease with a Special Focus on Autism.
Specific gut bacteria direct the development of the mammalian immune system and confer protection from intestinal diseases; thus fundamental aspects of health are absolutely dependent on microbial symbiosis.
Western societies, recent epidemiologic and clinical reports have revealed dramatic increases in the incidences of inflammatory (chronic disease) and immune disorders including inflammatory bowel disease, asthma, type 1 diabetes, and multiple sclerosis (see below slide).
The “American Gut” project and others, have documented how different the Western microbiome (blue on below slide) is from the rest of non-Western microbiomes.
The hygiene hypothesis proposed two decades ago speculated that these increases are the result of lifestyle changes and medical advances that reduce exposure to microbial pathogens AND that knock out our microbiota.
Astonishingly, the disorders involve a common immunologic defect found in the absence of intestinal bacteria. The question then becomes: After eons of co-evolution with our microbial partners, have societal advances (including sanitation, ‘western’ diets, and antibiotics) paradoxically affected human health adversely by reducing our exposure to health-promoting bacteria both from the environment and from our microbiota? Studies now say, “Yes!”
WE ARE SICKER WHEN WE HAVE LESS BACTERIA ONBOARD WITHIN OUR MICROBIOME
Humans depend on crucial by-products of the microbiome which includes the collective genomes of our intestinal bacterial species, which outnumber our human genome by 10:1. The microbiome harnesses nutrients through fermentation of complex sugars passing through the intestine and generates a large array of metabolites.[Fernandes et al 2014] is a goldmine for short chain fatty acid (SCFA) discussion, but for now, understand that it is a very important metabolite as it affects immunity, strengthens the intestinal wall, and fuels the cells lining the gut (see below slide).
Many Americans are SCFA deficient due to the low fiber consumption inherent in the Standard American Diet – but the story does not end there. As noted above, SCFAs (mainly butyrate, but also propionate and acetate) are found to be increased in overweight and obese people. This is contradictory to the current thinking, that increased fiber reduces the risk of obesity. [Woting et al 2016] dives into the why and hows behind this seemingly contradictory finding with discussion too on the role of chronic inflammation from the pro-inflammatory microbiome composition that produces the SCFAs (and more). The pro-inflammatory situation permits LPS (and more) to cross the gut barrier with consequent detrimental systemic reach. Thus, it seems to be the microbiome community that dictates the metabolism of SCFA and thus resultant health ramifications, and an excess of SCFA may not be healthy see the post link Prebiotics, Gut Health, and Weight Loss (Dr. Ruscio).
![[Woting et al 2016] The Intestinal Microbiota in Metabolic Disease](https://i0.wp.com/biomeonboardawareness.com/wp-content/uploads/2014/10/Woting-et-al-2016-Intestinal-Microbiome-in-Metabolic-Disease.png?fit=300%2C289&ssl=1)
⇒ When the microbiome community diversity and/or those species critical for providing beneficial by-products are reduced, we lack the optimal life sustaining necessities for immunity and thus negatively impact health, wellness, and vitality.
⇒ Additionally, pathogenic microbiota can slip into the ecosystem void and flourish furthering the risk of disease.
Advances using genomic, microbiologic, immunologic methods and animal models in the last few years now make it possible to mine this untapped reservoir for beneficial microbial molecules. Many labs (see references below) have the goals of defining the molecular processes evolved by symbiotic bacteria that mediate protection from inflammatory (chronic disease) and autoimmune diseases.
Intriguing connections between gut bacteria and behavioral and neurodegenerative disorders, autoimmunity, and inflammatory chronic disease have been found (see the drop down menu on the top right sidebar titled “The Science Behind Food And Disease” for specific disease/microbiome correlations which is also pictured on the below slide, but note: correlation does not mean causation). Labs are now investigating how the microbiome regulates the gut-immune-chronic disease, autoimmune, as well as brain axis which may lead to novel therapies for enigmatic diseases based upon an understanding of the beneficial immune, organ/tissue or neurological responses promoted by symbiotic gut bacteria which may lead to the development of natural therapeutics based on entirely novel biological principles.
References: There are many labs involved in collaboration with the microbiota research discussed on this page. Some of my favorites are:
- Sarkis Mazmanian Lab (Caltech): autism – Humans co-evolved with bacteria. There are three parts of the human that continue to evolve through-out one’s lifetime: the brain, the immune system and the microbiota. We study how these three constantly evolving parts interact and influence health and disease.
- The Knight Lab (University of Colorado Boulder) This page links to their research publications.
- The Jeff Gordon Lab (Wash U) on obesity and malnutrition.
- Jonathan Eisen’s Lab (UC Davis) on brain analolgy.
- Maria Gloria Dominguez-Bello Lab (NYU) all about babies.
- The Ruth Ley Lab (Cornell) all about babies and the vaginal microbiome, obesity and malnutrition. This article is a great launch point: “Meanwhile, after birth, the children’s microbiotas resembled those of the mothers’ first trimester samples [despite the changes that occurred in the third trimester]. Ley speculates that physiological changes that occur during pregnancy alter the microbial community, which, in turn, creates a positive-feedback loop sustaining conditions seen in metabolic syndrome. “The body might be using the microbes as a tool,” she says. “You alter the microbiota, and they give you the changes in metabolism that you want.” “That is pretty suggestive that the microbiome is at least contributing to the change, or maybe driving it,” says David Relman, a microbiologist at Stanford University in California who is looking for associations between pregnancy microbiomes and pre-term birth.”
- Dr. Emma Allen-Vercoe who presented at the “1st International Symposium on the Microbiome in Health and Disease with a Special Focus on Autism” on live fermentation of the gut microbiome.
- The Human Microbiome Project
- “The Human Microbiome: A True Story about You and Trillions of Your Closest (Microscopic) Friends,” Lita M. Proctor
As always, best of health through awareness,
References
- Dr. Rob Knight’s talk, Saturday, October 18, 2014, listed eleven factors that optimize the gut microbiome based on the American Gut Data cautioning all is preliminary.
- “Can We Eat Our Way To A Healthier Microbiome? It’s Complicated.
- Crowd sourcing project “American Gut” Dr. Knight and Jeff Leach, founders.
- [Cantinean et al 2018] An overview on the interplay between nutraceuticals and gut microbiota.
- An update to the American Gut data just published [McDonald et al 2018] American Gut: an Open Platform for Citizen Science Microbiome Research.
- Fiber Additives Starve Gut Microbes. They Eat Mucus Lining
- [Filocamo et al 2012] Effect of garlic powder on the growth of commensal bacteria from the gastrointestinal tract.Garlic actually has antimicrobial properties, which paradoxically, could also be good thing for our microbiomes. One study shows that garlic hurts some of the bad bacteria in our guts while leaving the good guys intact.
- [Fernandes et al 2014] Adiposity, gut microbiota and faecal short chain fatty acids are linked in adult humans.
- [Yatsunenko et al 2012] Human gut microbome viewed across age and geography. Links meat to differences in the gut microbiome when compared to diets that heavily rely on plant foods.
- [David et al 2013] Diet rapidly and reproducibly alters the human gut microbiome. Links meat to differences in the gut microbiome when compared to diets that heavily rely on plant foods.
- [Koeth et al 2013] Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis.
- [Slashinski 2014] Investigators’ Perspectives on Translating Human Microbiome Research into Clinical Practice
- Dr. Rob Knight, “How microbes could cure disease: Rob Knight at TED2014”
- ‘Animated Life: Seeing the Invisible’.
- [Koren et al 2013] Host remodeling of the gut microbiome and metabolic changes during pregnancy.
- [Woting et al 2016] The Intestinal Microbiota in Metabolic Disease.
- [Vijay-Kumar et al 2010] Metabolic Syndrome and Altered Gut Microbiota in Mice Lacking Toll-Like Receptor 5.
- [Aagaard et al 2012]A Metagenomic Approach to Characterization of the Vaginal Microbiome Signature in Pregnancy
- Microbiome, What Disrupts It?
- Microbiome Rules, What Is It?
- Dr. Emma Allen-Vercoe presented at the 1st International Symposium on the Microbiome in Health and Disease with a Special Focus on Autism. Her lab studies fermenting real time gut microbiome.
- Prebiotics, Gut Health, and Weight Loss (Dr. Ruscio), an excess of SCFA may not be healthy post link.
- Key microbiome researcher lab references with links follow which are not repeated here, for simplicity.
Last updated: August 22, 2018 at 11:35 am to add [Cantinean et al 2018] and the 2018 American Gut update info. Added in Summary section: ” A KEY finding was that the more vegs consumed (30 different each week is BEST), the more diverse the microbiome, and that is thought to be associated with health and improved immune status since MANY chronic diseases (see the below Table) have changes in microbiome diversity AND composition, see [Cantinean et al 2018]. A 2018 update on the American Gut data just published, [McDonald et al 2018], and it still says to eat 30 different vegs each week!” Tables and Figures from [Cantinean et al 2018], showing microbiome associations with disease, was added as was the “Reference” section.
Prior update Feb 4, 2018 was a major re-write for easier reading.
Prior update Nov 3, 2017 added SCFA excess may not be good as discusssed in obesity post link Prebiotics, Gut Health, and Weight Loss (Dr. Ruscio). Prior update June 11, 2017 was for SEO Optimization.
Towards large-cohort comparative studies to define the factors influencing the gut microbial community structure of ASD patients, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4355505/
The first attempt at collecting detailed diet information by the American Gut Project yielded limited results (though a correlation in diversity with the number of different types of plants consumed was observed). Variables such as the approximate percentage of fat consumed over the course of a week had incredible variance and in many cases were outside of reality. In its second attempt at diet, the American Gut Project decided to take a two-pronged approach, one using a generalized diet questionnaire that lacked free text entry and contained questions about the frequency of consumption (e.g. in an average week, how often do you consume at least 2–3 servings of fruit in a day?), and the second to use a validated food frequency questionnaire through a professional service called Vioscreen.
The human microbiome: How to feed your gut http://www.baltimoresun.com/health/blog/bs-fo-microbiome-20150304-story.html
Get in my belly: Eating for 2 … trillion
Ways to improve the microbiome include prebiotics, such as fibrous foods, and probiotics, which are live bacteria or yeasts eaten in common foods or taken as a supplement. Both pre- and probiotics are important for proper microbial balance. To increase both the diversity and composition of your microbiota, bump up your daily intake of both pre- and probiotics from a variety of sources. Eat more plants, especially raw or minimally processed. Cook them lightly or eat them raw: seed, bud, root, stem, leaf, fruit and flower.
Prebiotic fiber needs to reach the bacteria living in the large intestine: the last stop in the GI tract. To do this, the food needs to be indigestible by both stomach acidity and alkalinity of the small intestine. Foods such as nuts, seeds, beans, whole grains, roots, leaves, fibrous skins and stalks may accomplish this task. Limit cooking times, which breaks down food fibers, easing digestibility and leaving little for the microbiome to ferment. Choose steel cut oats, raw or lightly cooked veggies, fresh and dried fruits, and whole wheat pasta cooked al dente.
Some A to Z foods to include in your daily diet: apples, artichokes, asparagus, avocados, bananas, berries, barley, bran flakes, Brussels sprouts, cabbage, cucumbers, corn, dates and other dried fruits, edamame, eggplant, flax seeds, garlic, granola, hummus, inulin (from chicory root), jicama, kale, leafy greens (spinach, collards, Swiss chard), leeks, legumes, lentils, mushrooms, nuts (peanuts, tree nuts), onions, oats, oranges, peas, pears, pomegranates, popcorn, prunes, potatoes with skin, quinoa, raspberries (and other berries), raisins, sunchokes (tuber), sunflower seeds, spaghetti (whole wheat), tomatoes, turnips, uncooked (raw) veggies like carrots and broccoli, vegetable juices with pulp, walnuts, water chestnuts, watermelon, wheat bran, xigua (Chinese watermelon), yams and zucchini. Use this alphabet reference or aim to eat the rainbow to get more daily fiber. A fiber supplement or powder may not provide the same substrate for the microbes, so you should still increase your fiber intake from foods as much as possible.
Other ways to improve the microbiome include fermented foods that contain a brine, bacteria or yeast. Aim for one or two servings per day. These can include amazake (from rice), bean paste (miso), bean curd (tofu), beer, cottage cheese, chutney, fish sauce, kefir (from milk or coconut), kimchi (fermented cabbage), kombucha (tangy drink), lassi (spiced yogurt drink), natto (soybeans), pickled vegetables and other foods, poi (taro plant), rejuvelac (sprouted grain drink), salsa, seed cheese (fermented seed sprouts), sauerkraut, sourdough bread, sour cream (and crème fraiche), soy sauce, tempeh (fermented soybean cake), Tabasco and Worcestershire sauces, yakult (milk drink), and any yogurts (coconut or milk based). There are many others available worldwide as well as recipes for home-preparation, many of which are passed-down family favorites. Fermented foods are in vogue lately, but have been used safely for centuries. Probiotics are also found as supplements in capsules and powders, which may be a useful substitute.
Mushrooms, from the kingdom fungi, have a multitude of benefits still being studied. These versatile foods appear to positively impact the microbiome, further improving gut function and overall health. Choose only cultivated fresh or dried mushrooms from a grower or food store, as many backyard varieties can be poisonous. Safe species include cremini, chanterelle, enoki, maitake, morel, oyster, porcini, portabella, shiitake, trumpet, and the popular white button.
The complex interaction between food, the body and the microbiome will continue to unfold through scientific discovery, but for now: bon appétit!
For more information, check out these websites: The Human Microbiome Project, hmpdacc.org; Human Microbiota, nature.com/nature/focus/humanmicrobiota/; fiber: webmd.com/diet/healthtool-fiber-meter; mushrooms, mushroominfo.com/benefits.
Nutritionists from the University of Maryland Medical System regularly contribute guest posts to The Baltimore Sun’s Picture of Health blog (baltimoresun.com/pictureofhealth. This post is from Mindy Athas.
REGARDING REDUCED DIVERSITY: Less diversity can result in increased bacterial strains that cause inflammation representative of obesity, Type2 Diabetes and cardiovascular disease.
This Danish study, “Richness of human gut microbiome correlates with metabolic markers,” at http://www.nature.com/nature/journal/v500/n7464/pdf/nature12506.pdf (or read the University of Copenhagen scientific article “One in four has alarmingly few intestinal bacteria” at: http://news.ku.dk/all_news/2013/2013.8/one_in_four_has_alarmingly_few_intestinal_bacteria/ ) showed that one in four had 40% less gut bacteria than average. “This is a representative study sample, and the study results can therefore be generalized to people in the Western world,“ says Oluf Pedersen, Professor and Scientific Director at the Faculty of Health and Medical Sciences, University of Copenhagen. This population had reduced bacterial diversity and harbored more bacteria that caused low-grade inflammation of the body that is representative of obesity, Type 2 Diabetes, and some cardiovascular disorders.
Dr. Maria Gloria Dominguez-Bello estimated that 1/3 of the population has reduced microbiome as seen on this interview for the film “Microbirth”: http://microbirth.com/
The study, “Diversity, stability and resilience of the human gut microbiota,” at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3577372/ noted some dire consequences and ramifications of the altered and depleted microbiome status such as being associated with obesity6,7, malnutrition8, inflammatory bowel diseases (IBD) 9,10, neurological disorders11, and cancer12. (see article for interacting links).
How microbes could cure disease: Rob Knight at TED2014
http://blog.ted.com/2014/03/19/how-microbes-could-cure-disease-rob-knight-at-ted2014/
Dr. Knight says. “It turns out that if you give children antibiotics in the first six months of life, they’re more likely to become obese later.”
Knight doesn’t mince words. “The three pounds of microbes that you carry around with you might be more important than every single gene you carry around in your genome,” he says. Microbes have been linked to heart disease, colon cancer and obesity in human beings and, in mice, to multiple sclerosis, depression and autism. But, of course, it’s hard to tell if this is correlation or causation. Knight shares with us a line of experimentation raising mice in a germ-free environment without microbes of their own. Then, microbes are introduced to see what happens. If these mice are introduced to microbes from obese mice, they get fatter than they do than when introduced to microbes from lean mice. They appear to put on weight because they eat more than a regular mouse. “The implication is that microbes can affect mammalian behavior,” says Knight.
So what happens when a microbe-free mouse is introduced to microbes from an obese human being? That’s right—it begins to eat more and gain weight. This suggests that the strategy of introducing microbes from one person to another could potentially be used as a medical intervention. Knight explains how his team is studying children in Malawi with a type of malnutrition called “kwashiorkor” that causes them to lose 30% of their body mass in a week. Could introducing new microbes help them recover?
“We need to develop a microbial GPS,” he says, “to understand where we are, where we want to go and what we need to do to get there.”
MWV #82: Rob Knight – The Microbiome Project, Jan 2014: http://www.youtube.com/watch?v=gI0vB2s8PE8 Filmed in Vancouver, Canada at the 2012 American Society for Microbiology (AAAS) meeting.
1. Human genome: we are 99.9% same.
2. Microbiome genome: we are 80 to 90% different. Any microbe abundant in one, may be completely missing or at a low enough abundance that it is undetectable in others.
3. Unknown if huge variation matters or not; does it affect our health.
4. Many connections now to microbes doing things affecting health, brain, obesity
5. How can probiotics work when we are all so different? FMT with CDiff has 95+percent cure rate.
6. 3 things we need to know: What does a good community look like, what does a bad community look like, how do we get from a bad community to a good community.
7. New Zealand (Dr. Knight is from here) was plagued by introduction on invasibe microorganisms in the environment. This is one thing worrying Dr. Knight, how do modulate the microbiome when we don’t know enough. How do we accurately predict what will happen when we introduce a new microbioal member into the community?
8. Can’t see the forest thru the trees, well here we can’t see the trees thru the forest. How much diversity are we missing with 16S rRNA? With gut not much new being discovered upon 16S rRNA sequencing at least with a healthy adult since the recent discovery of anerobic bacteria has now increased that which is culturable. Originally “The Great Plate Anamoly” was that only 1% seen under a microscope was culturable. BUT, other envrionments, like coal bins and habitation, seeing whole new diversity not even related to anything in the database. Green Genes has covered now 82%, ony 17% of the tree represents the human body.
9. Cloud computing will/is speeding up research. There’s hundreds of millions of sequences from many labs. Now, give Amazon a cc# and you get many CPU and a length of time for running thousands of gigabytes of RAM now have. Third world can take samples and extract DNA on site, send samples to US for analysis. Prior long time for research dramatically reduced. Success in Bangladesh with 100 children data regarding malnutrition. Trends with different feeding patterns now see quickly.
11. QUIME is open software. Upload data to cloud and combine it with global world database.
American Gut data and processing pipeline made available to researchers studying the microbiome
http://biofrontiers.colorado.edu/news/american-gut-data-now-available (July, 2014)
Rob Knight, a professor in the University of Colorado Boulder’s Department of Chemistry and Biochemistry, and a faculty member at the BioFrontiers Institute, is sharing the largest known dataset on the human microbiome and the software key to understand what it may reveal about the role of the millions of bacteria living in and on the human body. The data is from the American Gut Project and includes information from more than 3,000 participants, 101 million DNA sequences and 27 gigabytes of sequencing information. The data has been deidentified to remove personal information, which was collected from 3,238 participants ranging in age from newborns to octogenarians, and Paleo dieters to omnivores. The American Gut Project summary, dataset and processing notebook can be found at http://americangut.org.
“Microbes may be the missing piece of the puzzle that makes personalized medicine work, “ says Knight, describing how the effects of drugs, including toxicity and efficacy, can depend on what microbes you have. “Optimizing the microbes you have may be even more important than optimizing your lifestyle – although in many cases you may be able to optimize your microbes by optimizing your lifestyle.”
Among the interesting patterns emerging from the data:
•How much of their microbial diversity participants shared with others depended greatly on how recently they had taken antibiotics. Those participants who had taken antibiotics within the last year tended to have less shared diversity.
•Alcohol imbibers tended to have greater microbial diversity than those that don’t drink alcohol at all.
•Spikes in microbiome populations seem to occur around holidays: in July, and in November through January.
•There is no single organism that is found in every person, but some are more common across the population than others.
•People who sleep more, and who exercise outdoors, have more diverse microbiomes.
•As seen in other studies, the elderly resemble infants in certain respects of their microbiomes.
“Researchers will be able to frame their own data against the American Gut data for context or additional insight. The American Gut data are broader than any other known human microbiome dataset, with participants covering the full range of ages, BMIs and diet.” – Daniel McDonald, a student working in Knight’s lab.