Free shipping within the EU

First slide

Obesity – is the cause in the microbiome?

December 23rd, 2021  

The relationship between obesity and the gut microbiome

Chronic diseases are rapidly increasing worldwide, and obesity, which refers to severe overweight, is considered one of the main culprits (1). Although there are a variety of methods that attempt to prevent the ever-increasing weight gain, obesity remains a widespread problem. Thus, there is an urgent need to develop new solutions. Obesity-related diseases such as cardiovascular disease, diabetes, and cancer are among the leading causes of death, so researchers are striving to find new efficient treatments for these diseases (2).

The causes of obesity

A high-calorie diet is a causal factor in obesity and may also lead to alterations in the gut microbiome (3). In addition to dietary, lifestyle, and genetic factors, it is suspected that obesity may also result from a disruption of the gut microbiome, which affects metabolic function and the balance between food intake and energy expenditure (3).

The connection between the gut microbiome and body weight

It is well known that the gut microbiome has a tremendous impact on overall health and well-being. The bacteria in the gut influence the absorption, breakdown, and storage of nutrients and have potential effects on physiology (1). In addition to high caloric intake, overuse of antibiotics has also been linked to the occurrence of obesity (4). An imbalance in the gut microbiome, which is also known as dysbiosis, can promote the growth of harmful organisms that can cause chronic inflammation and thus plays an important role in the prevention of chronic metabolic and intestinal diseases (5). A balanced gut microbiome on the other hand, is considered an important factor in the prevention or alleviation of obesity and metabolic diseases (6). Thus, increasing beneficial bacteria while reducing harmful bacteria can contribute to better health and well-being (7).

By the way, with the myBioma microbiome analysis you can easily check from home whether your gut microbiome is in balance or whether you have a dysbiosis. Based on your results, you will receive scientifically based nutritional recommendations.

The microbiome determines appetite

The gut has come to be called the “second brain” because the microorganisms living there communicate directly with the brain and thus influence brain signals that are responsible for stimulating hunger and appetite (8). 

It’s all about the right ratio

In most studies, the ratio of Firmicutes to Bacteroidetes was found to be significantly higher in obese subjects (7). In addition, a study was conducted to investigate the differences in the gut microbiome between obese and nonobese Japanese subjects. Obese subjects had a significantly reduced number of Bacteroidetes and a higher ratio of Firmicutes to Bacteroidetes compared with nonobese subjects. Bacterial diversity was also lower in obese subjects than in nonobese subjects (9).

A study of obese and lean Chinese college students showed a negative correlation between BMI and diversity. Obese male subjects had a less diverse microbiome than individuals in the lean group. In addition, the composition of the microbiome in lean males was more complex and had a higher ratio of Bacteroides to Firmicutes.

What influence does diet have on weight and the gut microbiome?

Different diets have a different impact on the composition and diversity of the gut microbiome (10). In this context, the typical Western diet, which consists of the consumption of highly processed foods, a high intake of saturated fatty acids and sugars, and a low intake of vegetables, fruits, and fiber (11), upsets the gut microbiome (12).

Studies have shown that African children who eat a low-fat, high-fiber diet have higher diversity and fewer disease-causing bacteria. These children also have greater amounts of Bacteroidetes than European children, who have greater amounts of Firmicutes and Enterobacteriaceae (13).

In contrast, a high-fat, low-fiber diet has been shown to reduce gut microbial diversity (14), protective gut bacteria, and SCFA (short-chain fatty acids) (15). Intake of high-fiber foods (e.g., fruits, vegetables, and legumes) increased microbial diversity (14, 16) and was associated with reduced weight gain in humans, independent of caloric intake (17).

In addition, astaxanthin, one of the most potent antioxidants, and the medicinal mushroom Antrodia cinnamomea were shown to improve the gut microbiome in obese mice induced by a high-fat diet. Both prevented weight gain, improved fat and sugar metabolism, and regulated the balance of the gut microbiome (18, 19) by optimizing the ratio of Bacteroides to Firmicutes and improving Akkermansia (19). 

What influence does exercise have on our weight and the gut microbiome?

Sports activities have a positive influence on the gut microbiome. They promote microbial diversity and also the proliferation of butyrate-producing gut bacteria (20). One study compared changes in gut microbial diversity and composition in young adults engaged in moderate to intense physical activity. The study found an increase in microbial diversity, particularly in participants who also ate an adequate amount of fiber per day (21). In addition, an increase in Bacteroidetes and a decrease in Firmicutes were reported in obese adults after aerobic moderate to intense physical activity (22). It can be concluded that both exercise and a high-fiber diet have a positive effect on our “slimming bacteria.” 

You can read more about the connection between sport and gut health in our article: How are microbiome and sport related?

Taking a holistic view

Finally, several factors influence the diversity and composition of the gut microbiome and can lead to an imbalance associated with weight gain and obesity. In particular, diet, physical activity, dietary supplements, medications influence the gut microbiome. The influence of the gut microbiome on metabolism, hormone balance, and the brain may play an important role in weight control and obesity treatment..

We are already looking forward to further studies. Did you know that you can feed and increase the right bacteria in your gut? Try this recipe: Lentil and vegetable stew: food for your slimming bacteria. You can find even more simple and tasty recipes to optimally support your microbiome in the myBioma eBook: Microbiome food – recipes for your gut bacteria.


(1) Gentile CL, Weir TL. The gut microbiota at the intersection of diet and human health. Science. 2018 Nov 16;362(6416):776-780. doi: 10.1126/science.aau5812. PMID: 30442802.

(2) Wilkins LJ, Monga M, Miller AW. Defining Dysbiosis for a Cluster of Chronic Diseases. Sci Rep. 2019 Sep 9;9(1):12918. doi: 10.1038/s41598-019-49452-y. PMID: 31501492; PMCID: PMC6733864.

(3) Guirro M, Costa A, Gual-Grau A, Herrero P, Torrell H, Canela N, Arola L. Effects from diet-induced gut microbiota dysbiosis and obesity can be ameliorated by fecal microbiota transplantation: A multiomics approach. PLoS One. 2019 Sep 23;14(9):e0218143. doi: 10.1371/journal.pone.0218143. PMID: 31545802; PMCID: PMC6756520.

(4) Podolsky SH. Historical Perspective on the Rise and Fall and Rise of Antibiotics and Human Weight Gain. Ann Intern Med. 2017 Jan 17;166(2):133-138. doi: 10.7326/M16-1855. PMID: 28114473.

(5) Turroni F, Ventura M, Buttó LF, Duranti S, O’Toole PW, Motherway MO, van Sinderen D. Molecular dialogue between the human gut microbiota and the host: a Lactobacillus and Bifidobacterium perspective. Cell Mol Life Sci. 2014 Jan;71(2):183-203. doi: 10.1007/s00018-013-1318-0. Epub 2013 Mar 21. PMID: 23516017.

(6) John GK, Mullin GE. The Gut Microbiome and Obesity. Curr Oncol Rep. 2016 Jul;18(7):45. doi: 10.1007/s11912-016-0528-7. PMID: 27255389.

(7) Fischer N, Relman DA. Clostridium difficile, Aging, and the Gut: Can Microbiome Rejuvenation Keep Us Young and Healthy? J Infect Dis. 2018 Jan 4;217(2):174-176. doi: 10.1093/infdis/jix417. PMID: 28968708; PMCID: PMC5853914.

(8) Lankelma JM, Nieuwdorp M, de Vos WM, Wiersinga WJ. The gut microbiota in internal medicine: implications for health and disease. Neth J Med. 2015 Feb;73(2):61-8. PMID: 25753070.

(9) Kasai C, Sugimoto K, Moritani I, Tanaka J, Oya Y, Inoue H, Tameda M, Shiraki K, Ito M, Takei Y, Takase K. Comparison of the gut microbiota composition between obese and non-obese individuals in a Japanese population, as analyzed by terminal restriction fragment length polymorphism and next-generation sequencing. BMC Gastroenterol. 2015 Aug 11;15:100. doi: 10.1186/s12876-015-0330-2. PMID: 26261039; PMCID: PMC4531509.

(10) Oriach CS, Robertson RC, Stanton C, Cryan JF, Dinan TG. Food for thought: the role of nutrition in the microbiota-gut-brain axis. Clin Nutr Exp. 2016;6:25–38. doi: 10.1016/j.yclnex.2016.01.003.

(11) Zinöcker M.K., Lindseth I.A. The Western diet–microbiome-host interaction and its role in metabolic disease. Nutrients. 2018;1010:365.

(12) Noble EE, Hsu TM, Kanoski SE. Gut to Brain Dysbiosis: Mechanisms Linking Western Diet Consumption, the Microbiome, and Cognitive Impairment. Front Behav Neurosci. 2017 Jan 30;11:9. doi: 10.3389/fnbeh.2017.00009. PMID: 28194099; PMCID: PMC5277010.

(13) De Filippo C, Cavalieri D, Di Paola M, Ramazzotti M, Poullet JB, Massart S, Collini S, Pieraccini G, Lionetti P. Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. Proc Natl Acad Sci U S A. 2010 Aug 17;107(33):14691-6. doi: 10.1073/pnas.1005963107. Epub 2010 Aug 2. PMID: 20679230; PMCID: PMC2930426.

(14) Simpson HL, Campbell BJ. Review article: dietary fibre-microbiota interactions. Aliment Pharmacol Ther. 2015;42:158–179. doi: 10.1111/apt.13248.

(15) Agus A, Denizot J, Thévenot J, Martinez-Medina M, Massier S, Sauvanet P, Bernalier-Donadille A, Denis S, Hofman P, Bonnet R, Billard E, Barnich N. Western diet induces a shift in microbiota composition enhancing susceptibility to Adherent-Invasive E. coli infection and intestinal inflammation. Sci Rep. 2016 Jan 8;6:19032. doi: 10.1038/srep19032. PMID: 26742586; PMCID: PMC4705701.

(16) Zhang N, Ju Z, Zuo T. Time for food: The impact of diet on gut microbiota and human health. Nutrition. 2018 Jul-Aug;51-52:80-85. doi: 10.1016/j.nut.2017.12.005. Epub 2018 Feb 5. PMID: 29621737.

(17) Menni C, Jackson MA, Pallister T, Steves CJ, Spector TD, Valdes AM. Gut microbiome diversity and high-fibre intake are related to lower long-term weight gain. Int J Obes (Lond). 2017 Jul;41(7):1099-1105. doi: 10.1038/ijo.2017.66. Epub 2017 Mar 13. PMID: 28286339; PMCID: PMC5500185.

(18) Chang CJ, Lu CC, Lin CS, Martel J, Ko YF, Ojcius DM, Wu TR, Tsai YH, Yeh TS, Lu JJ, Lai HC, Young JD. Antrodia cinnamomea reduces obesity and modulates the gut microbiota in high-fat diet-fed mice. Int J Obes (Lond). 2018 Feb;42(2):231-243. doi: 10.1038/ijo.2017.149. Epub 2017 Jun 20. PMID: 28630461; PMCID: PMC5803574.

(19) Wang J, Liu S, Wang H, Xiao S, Li C, Li Y, Liu B. Xanthophyllomyces dendrorhous-Derived Astaxanthin Regulates Lipid Metabolism and Gut Microbiota in Obese Mice Induced by A High-Fat Diet. Mar Drugs. 2019 Jun 5;17(6):337. doi: 10.3390/md17060337. PMID: 31195737; PMCID: PMC6627754.

(20) Allen JM, Mailing LJ, Niemiro GM, Moore R, Cook MD, White BA, Holscher HD, Woods JA. Exercise Alters Gut Microbiota Composition and Function in Lean and Obese Humans. Med Sci Sports Exerc. 2018 Apr;50(4):747-757. doi: 10.1249/MSS.0000000000001495. PMID: 29166320.

(21) Whisner CM, Maldonado J, Dente B, Krajmalnik-Brown R, Bruening M. Diet, physical activity and screen time but not body mass index are associated with the gut microbiome of a diverse cohort of college students living in university housing: a cross-sectional study. BMC Microbiol. 2018 Dec 12;18(1):210. doi: 10.1186/s12866-018-1362-x. PMID: 30541450; PMCID: PMC6291939.

(22) Santacruz A, Marcos A, Wärnberg J, Martí A, Martin-Matillas M, Campoy C, et al. Interplay between weight loss and gut microbiota composition in overweight adolescents. Obesity. 2009;17:1906–1915. doi: 10.1038/oby.2009.112.


Über den Autor

Listen to your gut!

Teile diesen Artikel


Vitamin D and the intestinal microbiome

Can you already see the Autumn leaves? This means that Summer is…

September 21st, 2023 • Cátia Pacífico

The influence of the gut-microbiome on our skin

The gut-skin axis Our gut microbiome is involved in many important physiological…

September 7th, 2023 • Deniz Inan

Guest articles

Are sweeteners and sugar substitutes bad for our gut microbiome?

It's no longer a secret that in today's world, high sugar consumption…

September 1st, 2023 • Christian