The Gut Microbiome and Obesity
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The gut microbiome consists of trillions of bacteria which play an important role in human metabolism. Animal and human studies have implicated distortion of the normal microbial balance in obesity and metabolic syndrome. Bacteria causing weight gain are thought to induce the expression of genes related to lipid and carbohydrate metabolism thereby leading to greater energy harvest from the diet. There is a large body of evidence demonstrating that alteration in the proportion of Bacteroidetes and Firmicutes leads to the development of obesity, but this has been recently challenged. It is likely that the influence of gut microbiome on obesity is much more complex than simply an imbalance in the proportion of these phyla of bacteria. Modulation of the gut microbiome through diet, pre- and probiotics, antibiotics, surgery, and fecal transplantation has the potential to majorly impact the obesity epidemic.
KeywordsMicrobiome Obesity Microbiota Diet Prebiotic Probiotic Microbial balance Bacteroidetes Firmicutes
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Conflict of Interest
George Kunnackal John and Gerard E. Mullin declare that they have no conflict of interest.
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This article does not contain any studies with human or animal subjects performed by any of the authors.
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- 10.Okeke F, Roland BC, Mullin GE. The role of the gut microbiome in the pathogenesis and treatment of obesity. Glob Adv Health Med. 2014;3(3):44–57.Google Scholar
- 11.Mullin GE. Gut Microbiome imbalance: pathways to weight gain and illness. Alternative and Complementary Therapies. 2015;21(4):161–62.Google Scholar
- 12.WHO. BMI classification. In: World Health Organization; 2015. http://apps.who.int/bmi/index.jsp?introPage=intro_3.htm
- 17.Mullin GE. The gut balance revolution: boost your metabolism, restore your inner ecology, and lose the weight for good! Emmaus: Rodale; 2015.Google Scholar
- 18.•Wallace JG, Gohir W, Sloboda DM. The impact of early life gut colonization on metabolic and obesogenic outcomes: what have animal models shown us? J Dev Orig Health Dis. 2016;7:15–24. This paper reviews early gut colonization in animal models focusing especially on the role of the early gut microbiome in impacting disease later in life. CrossRefPubMedGoogle Scholar
- 28.Armougom F, Henry M, Vialettes B, Raccah D, Raoult D. Monitoring bacterial community of human gut microbiota reveals an increase in lactobacillus in obese patients and methanogens in anorexic patients. PLoS One. 2009;4(9):e7125. doi: 10.1371/journal.pone.0007125.
- 35.Sotos M, Nadal I, Marti A, et al. Gut microbes and obesity in adolescents. Proceed Nutr Soc. 2008;67:null-null.Google Scholar
- 37.Zhang H, DiBaise JK, Zuccolo A, et al. Human gut microbiota in obesity and after gastric bypass. Proceedings of the National Academy of Sciences; 2009.Google Scholar
- 38.•Albenberg LG, Wu GD. Diet and the intestinal microbiome: associations, functions, and implications for health and disease. Gastroenterology. 2014;146:1564–72. This paper reviews the role of diet in impacting gut microbiome and its contribution in the pathogenesis of various disorders including obesity, coronary artery disease and inflammatory bowel disease. CrossRefPubMedPubMedCentralGoogle Scholar
- 40.Wang M, Li M, Chapkin RS, Ivanov I, Donovan SM. Fecal microbiome and metabolites differ between breast and formula-fed human infants. FASEB J. 2013;27:850–4.Google Scholar
- 45.••Chassaing B, Koren O, Goodrich JK, et al. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature. 2015;519:92–6. This study was one of the first studies focusing on dietary emulsifiers which are commonly used in the food industry. The authors demonstrated that the use of relatively low concentrations of two commonly used emulsifiers, carboxymethylcellulose and polysorbate-80, induced alterations in the gut flora associated with the development of colitis and onset of metabolic syndrome with increase in adiposity and weight and impaired glycemic control which was transmissible by fecal transplantation into germ free mice. CrossRefPubMedGoogle Scholar
- 46.Singh M, Mullin GE. Diet and environmental influences on the gut microbiome. In: Cohen A, vom Saal F editors. Integrative Environmental Medicine. Oxford: Univ Press; 2016.Google Scholar
- 49.Pineiro M, Asp NG, Reid G, Macfarlane S, Morelli L, Brunser O, Tuohy K. FAO Technical meeting on prebiotics. J Clin Gastroenterol. 2008;42(Suppl 3 Pt 2):S156–9.Google Scholar
- 57.Mullin GE, Delzenne NM. The human gut micobiome and its role in obesity and the metabolic syndrome. In: Mullin GE, Cheskin L, Matarese L, editors. Integrative weight management. New York: Springer Publ; 2014.Google Scholar
- 60.••Cox Laura M, Yamanishi S, Sohn J, et al. Altering the intestinal microbiota during a critical developmental window has lasting metabolic consequences. Cell. 2014;158:705–21. This study focused on the effect of low dose penicillin in weaning mice which caused changes in the ileal expression of genes involved in immunity as well as enhancement in the effect of diet induced obesity by its effects of gene expression in the liver, metabolic hormone levels and visceral adiposity with the trait being transferrable to germ free showing that the altered microbiota and not the antibiotics per se cause promotion of adiposity. CrossRefPubMedPubMedCentralGoogle Scholar
- 61.Thuny F, Richet H, Casalta JP, Angelakis E, Habib G, Raoult D. Vancomycin treatment of infective endocarditis is linked with recently acquired obesity. PLoS One. 2010;5:0009074.Google Scholar
- 66.Mullin GE. Probiotics in digestive disease. Nutr Clin Pract. 2012;27(2):300–2.Google Scholar
- 68.•Alang N, Kelly CR. Weight gain after fecal microbiota transplantation. Open Forum Infect Dis. 2015;2. The authors report a case of a 32 year old woman with a 41 lb unintentional weight gain following fecal transplantation from a related, overweight donor which highlights the importance of further studies to study the long term risks and benefits of fecal transplantation. Google Scholar
- 69.•Sweeney TE, Morton JM. The human gut microbiome: a review of the effect of obesity and surgically induced weight loss. JAMA Surg. 2013;148:563–9. This review focuses on the changes in the distal gut microbiome after Roux-en-Y gastric bypass and weight loss and discusses further clinical applications of studies of the distal gut microbiome. CrossRefPubMedPubMedCentralGoogle Scholar