The microbiome in our stomach has been linked to various aspects of mental and physical health. So what do we actually know about what's going on in there and how it affects our overall health?
With probiotics, fermented foods and kombucha all trending in recent years, we wanted to find out what all the fuss was about when it comes to our gut health.
Inside our stomachs and intestines are hundreds of different kinds of 'good' bacteria that help us digest food, making up what is known as the microbiome. This 'gut flora' is partly made up of bacteria we are born with (coming from our mothers) and partly dependent on our diet and lifestyle. Each person's mix of gut bacteria is unique.
Foods high in fiber from fruits and vegetables, along with yogurt, kefir, other fermented and pickled foods are believed to culture a healthier gut. A healthy balance of good bacteria also keeps 'bad' bacteria at bay, by squeezing them out for space to grow.
Researchers still have a lot to learn about how our microbiomes are created and how they affect our health throughout our lives. Below are some of their recent findings in the area of gut health.
1) Mental health can be affected by bacteria
Anxiety, depression, and autism have all been linked to bacteria in the gut. Referred to as the "gut-brain axis," this connection between our digestive tract and our brains still requires more study, but by better understanding the links and causation between the two, we could find new methods to treat certain disorders.
A study published this week from scientists in Belgium found that people suffering from depression are actually missing certain species of gut bacteria. Specifically, the microbes Coprococcus and Dialister.
Even with antidepressant treatment, the Coprococcus and Dialister species of bacteria were still absent from patients
While more needs to be understood about correlation and causation, this research may eventually lead to new methods of populating missing bacteria species in patients.
2) There's a lot in there — mapping the biome
Researchers from institutions in the UK, Canada, and Australia have worked on a project to map all the bacteria present in human gastrointestinal (GI) tracts. Called the Human Gastrointestinal Bacteria Culture Collection, the scientists have cataloged 273 species of bacteria so far.
They hope this research, much like the Human Genome Project, will lead to a greater understanding of what each bacteria's function is in the human body.
Read more: Pooping in the name of science
3) Links to disease
Scientists have been able to draw correlations between certain diseases, like type 2 diabetes, Crohn's disease, ulcerative colitis, colon cancer, high blood pressure and heart disease, and an unhealthy gut. Comparisons of healthy people and people with these ailments show a clear difference in the bacteria in healthy individuals versus those who are sick.
This may not be entirely surprising as the bacteria in your GI tract help you digest food and these diseases are either located in the GI tract or are highly correlated with what we eat.
Read more: Does gut flora cause multiple sclerosis?
4) Healthy people may not need probiotics
The use of probiotics to promote a healthy gut has been largely unsubstantiated and even contradicted by scientific studies.
Probiotics can come in the form of pills or from food and drinks like kombucha, which contains live cultures
Scientists at the Weizmann Institute of Science in Israel found that healthy people's gut microbiomes were actually resistant to letting new bacteria from probiotics colonize their GI tracts. Basically, they already had enough healthy bacteria that was thriving inside them, so there was no room for additional bacteria to take hold.
Instead, the study's author suggested, probiotics should be tailored for patients based on the needs of their particular microbiome.
5) Taking probiotics while on antibiotics
Antibiotics, as their name suggests, kill off bacteria in the body — both good and bad. People on antibiotics will often take probiotics to counter the negative effects of antibiotics and replenish their system with healthy bacteria.
The same researchers at the Weizmann Institute of Science who discovered that healthy GI tracts resisted probiotic colonization, found that a person taking probiotics while on antibiotics does populate probiotic strains of bacteria in the body. However, taking probiotics actually slowed down the repopulation of a person's normal gut bacteria.
Yogurt, fruit, and whole grains are all prebiotic foods that feed bacteria and can help lower blood pressure
6) Pre-biotics and lower blood pressure
While probiotics have become popular supplements and foods with probiotics have been recently trending, you may be less familiar with prebiotics.
These foods, like yogurt, contain things that bacteria need to digest in order to make certain chemicals. Those chemicals then get into our bloodstream and can help lower blood pressure. Fibrous foods are good prebiotics for many types of bacteria. These include fruits and vegetables like bananas, onions, garlic, asparagus, and leeks, as well as whole grains.
While researchers do not yet understand all the ways in which our gut is intertwined with our overall health, this field of study has been increasingly highlighting the importance of the little world of bugs inside of us, that help us digest food and keep things regular.