You might be wondering what I am drinking, or “why gut health matters?”, both are great questions! To start out, I’m drinking a kefir smoothie. A probiotic that you will soon learn more about near the bottom of this post. To answer your second question of “why gut health matters”, you must keep reading on. I suggest warming up your brains though because this is an article filled with lots of new & trending research. Seriously, I love this kind of stuff. I can’t hide the nerd in me anymore now that this is posted.
Most people think of bacteria within the body as a cause of getting sick or developing certain diseases, but did you know that at all times there are actually billions of beneficial bacteria present within all of us? In fact, bacteria make up our microbiome.
Recently, the scientific community has really come to embrace the important role that bacteria have in fostering a strong immune system and keeping us healthy. Not only are all bacteria not detrimental to our health, but some are actually crucial for boosting immunity, keeping our digestive systems running smoothly, our hormone levels balanced, and our brains working properly.
So, what is the microbiome, why is it so important, and how can we protect it?
The term microbiome is “a collection of different microbes(bacteria) and their functions or genes found in an environmental habitat.” (1) It is an integral internal ecosystem that benefits our gut health and the immune system.
Someone with normal gut health has over 35,000 bacterial species(1); unique for each individual. This picture below shows the distribution of the normal human gut flora(bacteria).
Current research has made it exceedingly apparent that the gut flora plays an important role in both our health and our vulnerability to disease.
Functions of gut flora include:
- Nutrient Metabolism:
- Metabolizes carbohydrates ——-> Butyrate, propionate, acetate (short-chain fatty acids (SCFAs) thought to play an important role in colon health; especially in terms of cancer prevention and reduction of inflammation) —> energy for host
- Metabolizes lipids(fats) —-> enhances the activity of lipoprotein lipase in adipose tissue
- Synthesis of conjugate linoleic acid—> which promotes the decrease in level of lipids in the blood, decrease the formation of fatty plaques in the arteries, decrease the risk of obesity and diabetes, help control blood sugar levels, and has immunomodulator properties
Synthesis of vitamin K and vitamin B
- Antimicrobial protection:
- Keep a check on the overgrowth of pathogenic strains by inducing local immunoglobulins (1)
- Bacteroides thetaiotaomicron and Lactobacillus innocua appear to be among the key individual species that drive this production(1)
- Drug Metabolism:
- Microbiome affects the metabolism and bioavailability of drugs
- Drugs can transform the composition of microbes (2)
- The exact mechanism remains unclear
- Maintain the integrity of the gut barrier
- 10% of the nerves connected from brain to gut send info form the BRAIN to the GUT:
- helps explain emotional eating
- in stressful situations our brain tells our digestive system to start saving energy for problem solving (example: nervous diarrhea, etc).
- 90% sends info from the gut to the brain:
- quality of nutrients you ate
- the hormones in the blood
- overall health status of the gut health. This contributes to how our overall health is doing. For example, studies show that people with IBS, SIBO, etc have higher levels of stress & anxiety because our gut signals to the brain something is wrong in our gut.
- Helpful bacteria provide direct protection for the lining of our large intestines, keeping out substances that would be harmful to us(1)
- 10% of the nerves connected from brain to gut send info form the BRAIN to the GUT:
Other reasons why gut health has gotten so much attention is because of the association between gut microflora and pathologies such as:
- increases proinflammatory cytokines=BAD)
- influence the development and function of the enteric nervous system (ENS) and immune system which affects central nervous system (CNS, aka brain) function(3)
- Diabetes & Obesity
- Decreased diversity of gut microbiota in obese and T2DM individuals(4)
- Low gene diversity and a less diverse composition of the microbiota associated with high BMI, fat mass, lower insulin sensitivity, dyslipidemia as well as increased markers of inflammation(4)
- Inflammatory bowel disease (IBD)
- Microbial imbalance or maladaption leads to inflammation which in turn alters the gut microbiota composition
- Low gene diversity and a less diverse composition of the microbiota associated with high BMI, fat
- Irritable bowel syndrome (IBS)
- Pathophysiologly of IBS still not well understood
- Chronic Abdominal cramping/discomfort with associated irregular bowel habits accompanied by +/- anxiety
- Small bowel bacterial overgrowth (SIBO)
- Imbalance and alteration in normal small intestinal gut flora, in terms of both volume and quality
- Non Alcoholic Fatty Liver Disease (NAFLD)
- High fat diet leads to deposition of lipids in liver by “bacterial overgrowth, gut leakiness, increased endotoxemia absorption, and inflammation” (5)
- Colorectal cancer
Any of those look familiar with you?? I thought so. There’s even more correlations too, see here:
Alterations in gut flora it could impact:
- Reduced capability to synthesize vitamin B12
- Reduced activities of microbial reductases
- Increased tendency for DNA alterations
- Elevated stress response, and immune dysfunction
Factors that contribute to variations in gut flora:
- Immune system: suppressed
- Medications: antibiotics, PPI, metformin, etc
- Age: the infant gut could be colonized by organisms even in utero
- “first microbiota profile is largely shaped by the mode of delivery” (1):
- Vaginal delivery – Ex. Lactobacillus and Prevotella (1)
- C.Section – maternal skin flora – Ex. Streptococcus, Corynebacterium, and Propionibacterium
- Type of early-life feeding: breast-fed vs formula-fed
- Geographic locations: Mostly based on the type of diet consumed
- “African children had a higher abundance of Prevotella” Agrarian diet
- European children consumed Western diet had higher amount of Bacteroides
- Consumption of high fiber diet is recommended
- Lack of fibers → substantial loss of microbial diversity
- When fiber is reintroduced, this effect is not fully reversed and increases in severity over multiple generations (6)
- Negative effects of Westernized Diet (although I recommend reading my post here that talks about my 5 tips and tricks for those seeking to lose weight and keep it off, gain a positive perspective about food, and make a happy lifestyle. The goal is to find balance)
- Increased consumption of sugar, and fatty foods.
- Greater amount of microbes that are linked to obesity
- Increased intestinal permeability
- Increased risk for chronic diseases like IBD, NAFLD, etc
- Probiotics, Prebiotics, and Polyphenols=All help to restore gut flora (1)
- Prebiotics= Non-digestible carbs that act as food for probiotics. Eg. leeks, garlic, onion, fibers
- Probiotics= Live bacteria and yeast that are helpful for digestion(diarrhea, constipation, bloating, cramping, and restoring gut flora, especially after antibiotic use). Sources come from foods(yogurt, sauerkraut, miso soup, kefir, kimchi, kombucha), supplements(oral pills, liquids, gummies) although most bacteria species coming from supplements don’t actually make it to the large intestine so it can be pretty $$, and probiotic skin repair cream(truthfully don’t know too much about these)
So, what does of this research mean to you? To me, it’s shown me that there is a much bigger equation to overall health than we previously thought. I deeper understand the importance of meditation and/or exercise to lower my stress levels, and aim to find at least 30 minutes a day. I understand the mechanisms of my food and strive to incorporate more foods that are high in fiber, add more probiotics to my diet (such as kefir) and am greater aware of the amount of added sugar and fatty foods I consume.
Prevention is my focus, and balance is my key.
- Jandhyala, Sai Manasa. “Role of the Normal Gut Microbiota.” World Journal of Gastroenterology : WJG. Baishideng Publishing Group Inc, 07 Aug. 2015. Web. 26 Mar. 2017.
Prados, Andreu, and Paul Enck. “The Role of ‘our Second Genome’ in Xenobiotic Metabolism and Therapeutic Outcomes.” Gut Microbiota for Health. N.p., 12 May 2016. Web. 26 Mar. 2017.
Kennedy, P. J., J. F. Cryan, T. G. Dinan, and G. Clarke. “Irritable Bowel Syndrome: A Microbiome-gut-brain Axis Disorder?” World Journal of Gastroenterology. U.S. National Library of Medicine, 21 Oct. 2014. Web. 26 Mar. 2017.
Bouter KE, van Raalte DH, Groen AK, Nieuwdorp M, Role of the Gut Microbiome in the Pathogenesis of Obesity and Obesity-Related Metabolic Dysfunction, Gastroenterology (2017), doi: 10.1053/j.gastro.2016.12.048.
Houghton, D., C. J. Stewart, C. P. Day, and M. Trenell. “Gut Microbiota and Lifestyle Interventions in NAFLD.” International Journal of Molecular Sciences. U.S. National Library of Medicine, 25 Mar. 2016. Web. 26 Mar. 2017.
Martens, Eric C. “Microbiome: Fibre for the Future.” Nature News. Nature Publishing Group, 13 Jan. 2016. Web. 26 Mar. 2017.
Additional & Suggested, Related Info:
- Ted Talk on the science of gut: https://www.youtube.com/watch?v=HNMQ_w7hXTA
- Han, M., C. Wang, P. Liu, D. Li, Y. Li, and X. Ma. “Dietary Fiber Gap and Host Gut Microbiota.” Protein and Peptide Letters. U.S. National Library of Medicine, 20 Feb. 2017. Web. 26 Mar. 2017.
- Bhattarai, Yogesh, David A. Muniz Pedrogo, and Purna C. Kashyap. “Irritable Bowel Syndrome: A Gut Microbiota-related Disorder?” American Journal of Physiology – Gastrointestinal and Liver Physiology. American Physiological Society, 01 Jan. 2017. Web. 26 Mar. 2017.
- Lopez-Legarrea, P., N. R. Fuller, M. A. Zulet, J. A. Martinez, and I. D. Caterson. “The Influence of Mediterranean, Carbohydrate and High Protein Diets on Gut Microbiota Composition in the Treatment of Obesity and Associated Inflammatory State.” Asia Pacific Journal of Clinical Nutrition. U.S. National Library of Medicine, n.d. Web. 26 Mar. 2017.
- Bures, J., J. Cyrany, D. Kohoutova, M. Förstl, S. Rejchrt, J. Kvetina, V. Vorisek, and M. Kopacova. “Small Intestinal Bacterial Overgrowth Syndrome.” World Journal of Gastroenterology. U.S. National Library of Medicine, 28 June 2010. Web. 26 Mar. 2017.