Volume 106, December 2025, 101410Author links open overlay panel, , , , , , , , , Abstract

The development of type 2 diabetes may be influenced by enterotypes and bacterial metabolites. The most important of these are short-chain fatty acids (SCFAs), which play a role in forming the gut-brain axis and in the process of lipogenesis. An increase in lipogenesis can lead to obesity. High levels of adipose tissue in the body trigger chronic inflammation and insulin resistance. This review examines how microbiota composition influences the pathogenesis of type 2 diabetes and the possibility of regulating microbiota through proper nutrition, fecal microbiota transplantation, and prebiotics and probiotics. Additionally, the review notes that an imbalance in the gut microbiota can contribute to diabetes progression and increase cancer risk through inflammatory and immune mechanisms.

Section snippetsOverview

According to the WHO, in 2022, the incidence of diabetes among adults aged 18 years and older was 14 %. In 2021, diabetes was the direct cause of 1.6 million deaths and 47 % of all deaths due to diabetes occurred before the age of 70 years. It is worth noting that during the same period, the incidence rate of other noncommunicable diseases, such as cardiovascular diseases, chronic respiratory diseases and cancer, decreased by 20 %. The prevalence of diabetes is increasing faster in low- and

Modern picture of the problem

Based on modern observations, it is believed that disruption of the composition and functions of the intestinal microbiota has a complex effect on a large number of physiological processes in the human body. Understanding this, we can point out that the risk of developing type 2 diabetes, depending on the above facts, is quite high (World Health Organization, 2024). Studying the qualitative and quantitative composition of intestinal bacteria can help in the development of various methods for

Enterotypes and their dependence on various factors

Bacteroides are most abundant in people with a particular diet that includes high consumption of meat, poultry, and seafood. In addition, members of this genus have a high saccharolytic potential (Martens et al., 2011). In contrast, Prevotella predominates in people who consume large amounts of vegetables and cereals, especially vegetarians (Kovatcheva-Datchary et al., 2015). Ruminococcus predominates in people who consume foods high in resistant or tolerant starch, which is mainly found in

Physiological effects of bacterial metabolites

A large number of sources indicate the contribution of bacterial metabolites to many physiological processes in the human body. During their life, bacteria can feed on nutrients that are not absorbed by intestinal cells. As a result, specific metabolites are released that can be absorbed by enterocytes and cause various physiological effects in the human body. The study of these effects allows us to understand the mechanisms of eating behavior, the pathogenesis of obesity and inflammatory

The gut-brain axis

Recently, the gut-brain axis (GBA) has received increasing attention from researchers around the world. Understanding the function of the GBA is important not only for basic research, but also for clinical application. The GBA is thought to consist of bidirectional communication between structures in the brain and cells in the intestinal wall. Both clinical and experimental data suggest that the gut microbiota has an important influence on GBA, interacting not only locally with intestinal

From gut to brain

According to some sources, GLP-1 and PYY are part of a complex network of gut hormones and neural pathways involved in transmitting information about food intake to the brain. The vagus nerve provides a pathway through which GLP-1 and PYY can influence the nucleus of the solitary tract in the dorsomedial medulla and then the appetite centers in the hypothalamus, suppressing the feeling of hunger. Receptors for GLP-1 are synthesized in the cells of the mesolimbic tract - centers of food

From brain to gut

Some sources suggest that the efferent component of GBA includes the nervous and endocrine regulation of intestinal functions. The nervous regulation of bacterial activity and intestinal functions is carried out by efferent nerve fibers of the vagus nerve. In this way, mucus secretion, peristalsis and permeability of the intestinal wall are regulated. The regulation of intestinal wall permeability is also associated with the development of inflammatory processes, which may lead to the

Mechanisms of inflammation development

The metabolic and endocrine factors mentioned above that influence the gut microbiota show the relationship between the occurrence of obesity and the presence of certain types of bacteria in the gut. Research in this area indicates that the accumulation of adipose tissue is closely associated with a decrease in oxygen availability and, as a result, cell damage, which leads to activation of the immune system and the release of inflammatory cytokines (Furman et al., 2019). Thus, the excess of

The connection between inflammation and insulin resistance

Observations indicate that the above processes increase the overall activity of the immune system and increase the production of anti-inflammatory cytokines. Some scientific works claim that the main group of receptors involved in the development of insulin resistance is TNFR (Shoelson et al., 2006). During normal functioning of the insulin receptor, autophosphorylation of its intracellular domain is triggered and further attachment of phosphate groups to the insulin receptor substrate (IRS),

Methods for regulating gut microbiota in the treatment of type 2 diabetes

Type 2 diabetes is currently one of the main medical problems. This disease has a number of prerequisites that can be stimulated by the intestinal microbiota. Accordingly, the microbiota plays a major role in the development of insulin resistance. The effect of bacteria and their metabolites on the risk of developing type 2 diabetes needs to be further investigated. Timely regulation and modification of the enterotype may be one of the possible treatment options for this disease. The

Probiotics

According to the Food and Agriculture Organization of the United Nations and the World Health Organization, probiotics are defined as “live microorganisms that, when administered in adequate quantities, confer a health benefit on the host”. Lactobacillus reuteri is a recognized probiotic agent capable of exerting antimicrobial activity against a wide range of gram-positive and gram-negative bacteria, as well as some species of fungi and protozoa (Spinler et al., 2008).

Probiotic strains of

Fecal microbiota transplantation

One study examined the effects of fecal microbiota transplantation in people with type 2 diabetes. Fecal microbiota transplantation involves changing the profile of the gut microbiome by injecting microorganisms from a donor. As a result of performing fecal microbiota transplantation on a group of 31 patients with type 2 diabetes, an increase in insulin sensitivity and a decrease in inflammatory processes were observed. However, no significant changes in body mass index were observed (Wu et

Proper nutrition

Dietary modification is one of the main strategies to improve the composition of microbial communities. In fact, easily fermentable fibers (such as β-glucan from whole grains, pectins from fruits, vegetables and legumes, and resistant starch) have been shown to increase the abundance of butyrate-producing bacteria, which may help reduce inflammation. It is noteworthy that people with enterotypes 1 and 2 experience weight loss with a diet high in plant fiber (including arabinoxylans) (

The role of the intestinal microbiota in the potential risk of developing cancer in type 2 diabetes mellitus

Type 2 diabetes mellitus is a condition associated with multiple metabolic dysregulations in neuroimmunoendocrine regulation. These dysfunctions are manifested by an imbalance of several metabolic factors, inflammatory mediators and the autonomic nervous system. The gut microbiota contributes significantly to the development of type 2 diabetes, which can lead to various comorbidities. In particular, the issue of the increased risk of oncogenesis associated with diabetes has recently gained

Conclusion

Thus, the gut microbiota has a complex impact on the human body. Bacterial metabolites produced throughout life play an important role in the regulation of the nervous, immune and endocrine systems, and also control a number of biochemical and cognitive processes that may be associated with increased or decreased risk of various diseases, particularly type 2 diabetes. Changes in the gut microbiome profile have been described to affect cognitive centers of the brain. Pathological regulation of

CRediT authorship contribution statement

Nataliya V. Zharova: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision. Filipp D. Mikhailidi: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision. Darya A. Kabanova: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision, Software. Alena Y. Tatarintseva: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision. Olga L. Polyakova: Writing –

Consent to participate

N/A.

Ethics approval

N/A.

Consent for publication

N/A.

Availability of data and materials

N/A.

Funding

N/A.

Competing of interests

There are no conflicts of interest.

Acknowledgments

N/A.

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