When people say “go with your gut,” they’re usually talking about instinct and intuition, but did you know that your digestive tract is home to trillions of microorganisms with a range of impacts on physical and mental health?
The latest research suggests that some 500-1000 unique species of bacteria, alongside an undetermined number of viruses, fungi, and other microbes, make up the microbiome of a healthy human digestive tract. While the primary function of the gut is to aid in the digestion of food, this community of microbes has been shown to interact with other systems such as the nervous system, immune system, and endocrine system. The last decade of scientific research on the human microbiome has illuminated the following seven surprising ways that the microbiome of the gut plays a role in other aspects of human health.
1. The Gut-Lung Axis
The “gut lung axis” refers to the bidirectional communications between the gut microbiome and the lung microbiome – a series of complex interactions through which gut bacteria and the metabolites they produce travel beyond the intestinal barrier and take on roles in the microbiome of the lung. Short-chain fatty acids (SCFAs) are one such metabolite known to play a role in response to allergic inflammation in the lungs. Multiple studies have explored the role of the gut-lung axis in chronic respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis.
The study of the gut-lung axis has opened up the possibility of new approaches such as dietary recommendations and oral administration of probiotics for lung health.
2. The Gut-Brain Connection
Those who attribute emotional reactions to their gut may actually be onto something. It has been established that bidirectional communication exists between the central and enteric nervous systems – in simple terms, a connection between emotional and cognitive centers in the brain and the world inside your gut. This dialogue is commonly referred to as the gut-brain axis.
Research from as far back as 2012 has suggested a role for the gut microbiota in regulating anxiety, mood, cognition, and pain. More recent studies have gone deeper on how microbes of the gut play a role in the production of key neurotransmitters such as serotonin (known for its roles in feelings of happiness and internal body clock) and gamma-aminobutyric acid (GABA) (known to help control feelings of fear and anxiety).
3. Gut Health and Probiotics for Weight Loss
Bacteroidetes and firmicutes are two abundant families of beneficial bacteria in the gut. Bodyweight may be related to the balance of these two families of bacteria. In short, a diverse gut microbiome with a variety of bacteria can help regulate metabolism, where dysbiosis (aka an imbalance of these bacteria) has been associated with increased weight.
Bacteria in the gut can also produce metabolites called short-chain fatty acids (SCFAs) and indoles that are known to play a role in metabolism, insulin sensitivity, appetite control, and the strength of intestinal barriers.
4. How a Healthy Gut Supports a Healthy Heart
The bacteria and metabolites they produce in the gut have also been studied in terms of their potential impacts on cardiovascular health. Studies have shown that various substances produced by the gut microbial community influence our risk for chronic diseases such as diabetes, high blood pressure, and high cholesterol. Chemicals or processes related to gut bacteria have been associated with a higher risk of heart failure, plaque build-up in the arteries, and major cardiovascular events like heart attack and stroke.
Nutrition tip: A high fiber diet and physical exercise are known to support a diverse microbial community in the gut, healthy weight management, and heart health. Prebiotic and probiotic supplements can also be used to support a healthy and diverse microbiome of the gut.
5. Gut Health Linked to Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a chronic inflammatory disease of the joints that – you guessed it – has also been linked with microbial dysbiosis. Studies have shown that the microbiome composition in healthy people is much more diverse when compared with those suffering from RA. Scientists at institutions such as the Mayo Clinic have begun to explore the role gut bacteria can play in prediction and treatment. Research also indicates that an imbalance in gut microbiome in the gut can adversely impact the effectiveness of certain arthritis medications.
Nutrition tip: A plant-based high-fiber diet rich in prebiotic and probiotic foods can help in maintaining a healthy gut and be beneficial in the management of inflammatory arthritis.
6. Gut Health and Probiotics for the Skin
One of the least intuitive microbiome interactions is the gut-skin axis, but skincare products with probiotic and prebiotic extracts with claims of treating acne and eczema are already hitting the market. The latest research suggests that gut microbes can help facilitate and modulate the anti-inflammatory responses at the level of the skin. Of particular interest is the role of the gut-skin axis in skin conditions such as acne, psoriasis, rosacea, and atopic dermatitis.
7. Could your gut hold the secret to a long and healthy life?
There are so many factors involved in the aging of the human body, making a direct relationship between gut health and aging a difficult one to establish. But a study published in 2021 suggests that for healthy aging, the composition of the microbiome should become more and more diverse after the age of 40.
Nutrition tip: There are plenty of prebiotic and probiotic supplements on the market that can help support a healthy microbiome, but for the purposes of biodiversification, fermented foods may hold the key. From pickles and pepperoncini to kombucha and kimchi, there are lots of fermented foods options available on grocery store shelves. Just keep an eye on nutrition labels if you’re watching your salt or sugar intake, as many fermented foods are high in sugar and/or salt!