Gut Bacteria May Influence Mental Health In Humans

Gut Bacteria May Influence Mental Health In Humans. Graphic © herbshealthhappiness.com. Image – Wikipedia (CC0 – PD)

New scientific study has demonstrated a connection between mental health and the balance of bacteria in the stomach. Did you know that your intestines are home to trillions of bacteria? Yes – although in one sense you are an individual, you are also an entire ecosystem. 😉 It’s ok: Gut bacteria play an important role in maintaining homeostasis or balance in the body. There are “good” bacteria that help keep the body functioning at optimal levels – and if these are compromised it can not only weaken the body against pathogens, but also alter the body’s fundamental chemistry in ways that influence wellbeing on a deep level.

Probiotic strains of bacteria have been proven to have beneficial effects on health, which contributes to the increase in probiotic drinks and snacks in the market. However, gut bacteria are greatly affected by our diet – as well as by accidental consumption of pathogenic (harmful) strains. When gut bacteria are altered, it can also have drastic effects on health. ^[1]

The Pros of Prebiotic Intake

Probiotic means “beneficial bacteria” while prebiotic is an ingestible fiber that fosters the growth of probiotics in the gastrointestinal tract. Schmidt, et. al. conducted a study on prebiotics in 2014, which was published in the same year. The focus of their study was the effects of prebiotic intake on mental health in humans. Forty-five volunteers who participated in the study were given one of two prebiotics or a placebo for a total of three weeks, after which they were assessed with a computerized test. The test was a “task battery” test that focused on facial expression recognition, self-referential processing, and emotional memory. ^[2]

The study concluded that the prebiotic supplements were able to reduce the levels of cortisol in the body, a hormone that is produced when a person is under stress. This suggests that the presence of good gut bacteria has anxiolytic effects, improving the body’s response to stressors. The results also showed that participants who were given prebiotic supplements were more vigilant to positive stimuli versus negative stimuli — this is also suggestive of an early-anxiolytic effect, because more anxious individuals are the opposite; they are more vigilant and responsive to threatening or negative cues.

While the researchers were unable to pinpoint exactly how gut bacteria are linked to mental health, they hypothesize that probiotics have effects on the body’s immune response, which could in turn be affecting the brain and mental health.

Other recent studies have also linked gut bacteria to health, with Clarke, et. al. revealing a link infant gut bacteria and child development. ^[3] Another study by Zhou and Foster published in 2015 focused on the gut-brain axis, the link between gut bacteria and brain health. ^[1] But what does this all mean for you?

How Gut Bacteria Health Is Damaged – And Maintained

Because the good bacteria in our intestines have the ability to affect our brain function, it means that we need to be more attentive to the food we eat and the medicines we take.

In America, GMO crops are sprayed with a pesticide called glyphosate. Glyphosate has been shown by study to alter the body’s microbiome ^[4] – the interplay between the body’s organ systems and gut bacteria – thereby inhibiting the production of enzymes that prevent the negative effects of chemicals found in food. This can cause a variety of gastrointestinal disorders, metabolic disease, and heart problems – not just in humans, but animals who are fed GMOs. ^[5]

It’s also widely known that broad spectrum antibiotics attack both the desirable and undesirable bacteria. This itself is an undesirable effect.

In addition to avoidance of things that are destructive to the body’s bacteria (where appropriate), it’s possible to boost the beneficial bacteria in the stomach – either through probiotic supplements or through foods that have natural probiotic content. Examples of the latter include natural yogurt, kefir, sauerkraut, kimchi and other fermented vegetables. Another interesting possibility is ginger ale which has been prepared in the traditional way – see our natural ginger ale tutorial here.

Note that probiotics may be contraindicated for people with intestinal injuries or ulcers.