How do stomach microbiota affect mental health in 18-25s?

In a recently published article International Journal of Molecular ScienceScientists have described the importance of the stomach-brain-microbiota axis in establishing optimal mental health in emerging adults (18-25 years).

Study: Drugs, guts, brain, but not rock and roll: The role of stomach microbiota in contemporary mental health and the well-being of emerging adults needs to be considered. Image Credit: Alpha Tauri 3D Graphics

Background

Emerging adulthood is a critical period for neuronal development, neuroplasticity, and maturation of the hypothalamic-pituitary-adrenal axis. During this period, stress responses, including fluctuations in hormonal levels and diverse activation of the hypothalamic-pituitary-adrenal axis, have a significant impact on the development of mental health. Studies have shown that mental illness is more likely to occur in adults during this period.

Gut microbiota is a collection of various microorganisms, including bacteria that live in the gastrointestinal tract. Various factors, including genetic factors, early life factors (maternal infection, antibiotic use, etc.), and environmental / lifestyle factors (diet, physical activity, stress, etc.) can seriously alter the structure and diversity of intestinal microbiota.

Recent evidence suggests that emerging adulthood is associated with a unique risk to abdominal microbiota. In emerging adults, abdominal microbiota is less diverse, simpler, and more volatile than in children, adolescents, and the elderly. In a recent article, scientists speculated that the stomach-brain-microbiota axis may play a role in determining mental health problems, which are increasing significantly in Western countries, possibly due to adverse lifestyle behaviors.

The interface between stomach microbiota and mental health probably depends on many factors. (AThe first is the input into the intestinal tract which shapes the microbiota accordingly (diet, medicine, antimicrobial, etc.). (B) Periods where microbiota diversity (alpha) goes through changes in healthy people, especially between the end of adolescence and early twenties, which can lead to variations in metabolic production affecting brain health. (C) Dissection of the adolescent brain, normally unstable microbiota of age group, promotion of desirable microbiota through physical activity / exercise and circadian rhythm, and less desirable microbiota using various substances. Part (C) Bian et al., Adapted from 2017. Image courtesy of Biorender (accessed 29 April 2022).

The stomach-brain-microbiota axis

The microorganisms that live in the stomach produce many important components, such as short-chain fatty acids, brain-derived neurotrophic factors, and neurotransmitters, which mediate communication between the intestines and the brain. An imbalance in the stomach’s microbiota can lead to the production of inflammatory cytokines mediated by microbial lipopolysaccharide (LPS), which subsequently affects the hypothalamic-pituitary-adrenal axis and stimulates the vaginal nerve.

Effects of stomach microbiota on mental health

According to the available literature, there is a link between stomach microbiota and mental health. In this regard, studies have shown that antibiotic-induced changes in abdominal microbiota are associated with altered emotional behavior. The stomach-brain-microbiota axis is known to play a significant role in the development of various neurological and psychiatric diseases, including Alzheimer’s disease, Parkinson’s disease, and autism spectrum disorders. Any imbalance in the abdominal microbiota during adolescence can lead to a cascade of events that have long-term negative effects on both physical and mental health.

Influence of environmental / lifestyle factors on stomach microbiota and mental health

Among the environmental factors most influential in shaping the intestinal microbiota are diet, drugs, and antimicrobial agents. Additionally, physical activity, sleep patterns, and substance use affect abdominal microbiota as well as mental health.

General findings for a variety of diets on the intestinal-brain-microbiome axis. (A) Micronutrients such as vegetables, fiber, vitamins D and C, probiotics and prebiotics, fermented foods, foods containing anti-inflammatory omega-3, low fat and low carbohydrate foods promote positive mental health. Bacteroides, prebhotela, fatty acids, bifodobacteria, lactobacilli, and interleukin (IL) -10, and fermicutus coccyx, Ruminococcus, coprocolytic, Yes. Gamma-induced proteins 10, IL-17, IL-12, c-reactive proteins, IL-2, tumor necrosis factor, and lipopolysaccharide. (B) High-fat, high-sugar, and ultra-processed foods increase bacterioids, bile acids, bilophila wadworth, enterobacteriaceae, formicuts, enterobacteriaceae, Escherichia, Klebsiella, and Shigella. Image created via Biorender (accessed April 29, 2022).

Diet

Dietary factors significantly affect the structure and diversity of intestinal microbiota. Excessive consumption of unhealthy foods (saturated fat, refined sugar, red meat, and low-fiber foods) and low consumption of healthy foods (fruits and vegetables) can cause microbial dysbiosis, characterized by changes in functional structure, diversity, and local distribution. , And the metabolic activities of the stomach microbiota.

Strong evidence suggests that a diet rich in vegetables, fruits, fiber, fermented foods, vitamins, probiotics and polyunsaturated fatty acids may help maintain stomach microbiota homeostasis and promote positive mental health. In contrast, high-fat, high-carbohydrate, and ultra-processed foods are associated with intestinal dysbiosis, inflammation, and poor mental health.

Physical activity

It is known that regular physical activity is important for maintaining metabolism and cardiovascular fitness and improving mental health. Additionally, in the context of stomach microbial diversity, physical activity is known to increase the levels of beneficial microorganisms and metabolites in the stomach.

The effects of physical activity may vary from person to person depending on age, gender, genetic makeup, body mass index (BMI), and dietary habits. Notably, intense physical activity can cause microbiota dysbiosis and inflammation of the stomach and lead to adverse health consequences. Therefore, the optimal level of physical activity needs to be personalized.

Use of substance

Excessive consumption of nicotine, alcohol, cannabis and illicit substances is frequently observed in emerging adults, especially those living in Western countries. These substances are known to have negative effects on both physical and mental health.

Neuronal nicotinic acetylcholine receptors are important for the development and maturation of the central nervous system. Nicotine consumption in early life can lead to addiction, cognitive decline and psychological disorders. In addition, nicotine consumption can cause gastrointestinal microbiota imbalance by increasing the permeability of intestinal mucosa and inhibiting mucosal immune responses.

Excessive alcohol consumption in early life can alter the frontal and temporal brain lobes and impair learning, memory, psychomotor speed, attention, executive function, and the neural networks associated with impulses. In the stomach, alcohol alters metabolic levels, increases inflammation, and impairs intestinal integrity.

Consumption of cannabis increases the activity of cannabinoid receptors and produces various health effects, including induction of gastric acid secretion, decreased intestinal motility, and intestinal permeability and inflammation. In addition, studies have shown that cannabis use in early life is associated with a decline in cognitive ability.

Sleeping pattern

Regular sleep patterns can be affected by a number of factors, including shift work, night light exposure, inconsistent eating times, unhealthy eating, and jet lag. Changes in sleep timing and pattern are more common in adolescents with mental disorders such as depression and anxiety.

Sleep disturbances can also interfere with the microbiome homeostasis of the stomach by increasing the number of harmful microorganisms and reducing the number of beneficial microorganisms and metabolites.