It’s the second part of my microbiome madness blog! For the past two weeks, I’ve been exploring with you the health implications of having the proper microbe composition lining your insides throughout your lifespan.
Some of you may be wondering why I’m dedicating so much time to this one contagious subject. Well, as I mentioned last week, I believe our little critter friends are the KEY to…
- Explaining the connection and contribution of our lifestyle choices in disease.
- Proving that death really may begin in the colon.
- The future of medicine! We are entering the end of “Pharmaggeden” and the era of Microbiome Madness!
The Link Between Microbe Composition & Health… in Adults
1. Liver Health: NASH (Nonalcoholic Steatohepatits)
A recent study discussed how the microbiome modulates liver health in adults. The authors state, “Recent studies suggest that the characteristics of the gut microbiota are altered in patients with obesity and fatty liver disease, and small intestinal bacterial overgrowth contributes to the pathogenesis of NASH by inducing altered gut permeability and endotoxemia.” (Endotoxemia is the presence of bacteria in the blood). 1
Interestingly, the researchers found that the bug family of Christensenellaceae, was enriched in individuals with a lower body mass index and if these microbes were transplanted from human subjects into germ-free mice , these bacteria protected the mice against weight gain. 1
2. The Fat Attack
This study demonstrated how our gut bugs may modulate metabolism by influencing the activity of brown fat is in mice. (Brown fat is a type of adipose tissue linked to calorie burning, especially with cold exposure). The study compared regular mice with normal gut bacteria to “germ-free mice” that were bred to contain no bacteria in their colon. According the Medical News Today, “They found that brown fat in the germ-free mice appeared to be more active and burned calories faster than in the regular mice.” 2
3. The Gut-Brain Axis
A study in Behavioural Brain Research discussed the relationship between gut health and the microbial modulation of the neurotransmitter serotonin:
The brain-gut axis is a bidirectional communication system between the central nervous system and the gastrointestinal tract. Serotonin functions as a key neurotransmitter at both terminals of this network. Accumulating evidence points to a critical role for the gut microbiome in regulating normal functioning of this axis. In particular, it is becoming clear that the microbial influence on tryptophan metabolism and the serotonergic system may be an important node in such regulation.3
Another study in Neurogastroenterology & Motility further expanded on the concept of the unique bacterial “fingerprint” of each individual and the relationship to gastrointestinal, neuroendocrine, and immune health:
The ability of gut microbiota to communicate with the brain and thus modulate behavior is emerging as an exciting concept in health and disease. The enteric microbiota interacts with the host to form essential relationships that govern homeostasis. Despite the unique enteric bacterial fingerprint of each individual, there appears to be a certain balance that confers health benefits. It is, therefore, reasonable to note that a decrease in the desirable gastrointestinal bacteria will lead to deterioration in gastrointestinal, neuroendocrine or immune relationships and ultimately disease. 4
Finally, there was the 2013 viral-article on the link between women who ate a fermented milk product and the impact it had on modulating brain activity. The authors reported:
Four-week intake of an FMPP (fermented milk product with probiotic) by healthy women affected activity of brain regions that control central processing of emotion and sensation.5
4. Stress Less with Bug Feeding
Another study demonstrated the effects of feeding gut bugs by comparing the intake of two prebiotics (fructooligosaccharides, FOS, or Bimuno®-galactooligosaccharides, B-GOS) verses taking a placebo (maltodextrin) daily. The study was for three weeks and included 45 subjects. The secretion of the stress hormone, cortisol , and emotional processing in healthy volunteers were measured to determine the link between fiber intake and emotional responses. Those who used one of the prebiotics had lower cortisol levels and paid less attention to negative stimuli:
Results: The salivary cortisol awakening response was significantly lower after B-GOS intake compared with placebo. Participants also showed decreased attentional vigilance to negative versus positive information in a dot-probe task after B-GOS compared to placebo intake. No effects were found after the administration of FOS. 6
5. Role in Cancer:
Various studies have demonstrated how the microbiome modulates colorectal cancer 7-8 and lymphoma. 9-10
6. Gut Health of Course!
Studies support a healthy microbiome balance and specific species can modulate IBS (Irritable Bowel Syndrome) and IBD (Irritable Bowel Disease) symptoms. 11-12
We CAN Alter Our Gut Bacteria!
If our gut bugs are so important, can we manipulate their diversity in order to optimize health? Medical News Today (MNT) reports that diet and exercise can be used to modulate a healthy microbiome:
According to the Mayo Clinic, a healthy diet can encourage the presence of good gut bacteria. They note that consuming fermented foods – such as miso and sauerkraut – increases the level of fermenting bacteria in the gut. In addition, fruits and vegetables contain fibers and sugars that can boost the health of gut bacteria.
Exercise may also be key to improving gut bacteria diversity, according to a study reported by MNT in June 2014.
The study, published in the journal Gut, compared the gut bacteria of 40 professional rugby players with that of two control groups. They found that the rugby players had much higher levels of Akkermansiaceae in their gut – a bacterium that has been associated with reduced risk of obesity. 13
The Dietary Shift
A study in Nature reported on the relationship between dietary intake and shifts in microbiota populations. The study discussed how changes can occur quit rapidly and the consumption of animal or plant products change microbial communities differently:
Long-term dietary intake in influences the structure and activity of the trillions of microorganisms residing in the human gut1, 2, 3, 4, 5, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals2, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease6. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles 14
The following 18 min video explores all the relationships between health, our microbiome composition, and how food shifts our gut bugs:
Now, click here for some more specifics on diet and microbiome health.
- Balisteri WF. Eschewing the Fat: What’s on the Horizon for Treating NASH? Medscape Gastroenterology > What’s Hot in Gastroenterology. March 10, 2015.
- Paddock C. Gut Bacteria May Have Role In Obesity. MNT. Februray 16, 2012.
- O’Mahonya AM, Clarkea G, Borrea YE, Dianan TG, Cryana JF. Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behavioural Brain Research. 277(15): 32-48. January 15, 2015. http://www.sciencedirect.com/science/article/pii/S0166432814004768
- Cryan JF1, O’Mahony SM. The microbiome-gut-brain axis: from bowel to behavior. Neurogastroenterol Motil. 2011 Mar;23(3):187-92. doi: 10.1111/j.1365-2982.2010.01664.x.
- Tillisch K, Labus J, Kilpatrick L, Zhiguo J, Stains J, Ebrat, B, et al. Consumption of Fermented Milk Product With Probiotic Modulates Brain Activity. Gastroenterology. 2013; 144 (7): 1394-1401.
- Schmidt K, Cowen P, Harner CJ, Tzortizis G, Errington S, Burnet PWJ. Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers. Psychopharmocology. December 2014. http://link.springer.com/article/10.1007%2Fs00213-014-3810-0
- Gut microbes may play a role in colorectal cancer. MNT. March 4 2014. http://www.medicalnewstoday.com/articles/273472.php
- Zackular JP, Rogers MA, Ruffin MT 4th, Schloss PD.The human gut microbiome as a screening tool for colorectal cancer. Cancer Prev Res. 2014 Nov;7(11):1112-21. doi: 10.1158/1940-6207.CAPR-14-0129. Epub 2014 Aug 7.
- Gut bacteria linked to immune system cancer, lymphoma. MNT. July 17, 2013. http://www.medicalnewstoday.com/articles/263484.php
- Yamamoto ML1, Maier I, Dang AT, Berry D, Liu J, Ruegger PM, Yang JI, Soto PA, Presley LL, Reliene R, Westbrook AM, Wei B, Loy A, Chang C, Braun J, Borneman J, Schiestl RH. Intestinal bacteria modify lymphoma incidence and latency by affecting systemic inflammatory state, oxidative stress, and leukocyte genotoxicity. Cancer Res. 2013 Jul 15;73(14):4222-32. doi: 10.1158/0008-5472.CAN-13-0022.
- O’Mahony L1, McCarthy J, Kelly P, Hurley G, Luo F, Chen K, O’Sullivan GC, Kiely B, Collins JK, Shanahan F, Quigley EM. Lactobacillus and bifidobacterium in irritable bowel syndrome: symptom responses and relationship to cytokine profiles. Gastroenterology. 2005 Mar;128(3):541-51.
- Lee KN, Lee OY. Intestinal microbiota in pathophysiology and management of irritable bowel syndrome. World Journal of Gastroenterology?: WJG. 2014;20(27):8886-8897. doi:10.3748/wjg.v20.i27.8886.
- Whitman H. The gut microbiome: how does it affect our health? MNT. March 11, 2015. http://www.medicalnewstoday.com/articles/290747.php
- David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE, Wolf BE, Ling AV, Devlin AS, Varma Y, Fischbach MA, Biddinger SB, Dutton R, Turnbaugh P. Diet rapidly and reproducibly alters the human gut microbiome. Nature. January 23, 2014. 505: 559-563. doi:10.1038/nature12820
images courtesy istockphoto.com