Why You Should Be Concerned About Gut Bacteria
“What we think of as human health is, in a big way, the result of the interaction between human cells and the gut microbiome, which has evolved over millions of years to safeguard our well-being… so long as we’re eating the fiber-rich vegetables, fruits, and legumes that they need to thrive,” said Kathie Madonna Swift and Joseph Hooper, authors of The Swift Diet: 4 Weeks to Mend the Belly, Lose the Weight, and Get Rid of the Bloat. Turns out that the everyday foods we consume can markedly effect our gut health, which affects everything from our waistline to our probability of getting a heart disease diagnosis. Time to start paying attention to the trillions of microbes that call your belly home! For a look at exactly why, we spoke with Swift and Hooper, who outlined five areas where eating to take care of your microbiome can have a major health pay-off.
1. Weight gain/Type 2 diabetes
The latest science is telling us that our microbiome exerts a major influence on how much weight we gain (or lose) from eating a given amount of food. Lean people are more likely to harbor a lot of gut bacteria and a wide range of bacterial species as compared to overweight people. When overweight people switch over to a plant-food-based diet, their gut bacteria start to resemble that of their lean counterparts and they begin to lose weight. How does it work? The vegetables, fruits, and legumes feed the good bacteria in our system.
The good bacteria are important because they may extract fewer calories from the food we eat and they also produce nutrients that build up the lining of the gut wall, which separates what’s going on in the gut from the rest of the body. If the good bacteria aren’t being well-fed with dietary fiber, the gut wall lining can grow “leaky,” letting gut contents spill into the bloodstream, which triggers inflammation throughout the entire body. Said inflammation can promote insulin resistance, which means the body has to produce more insulin with the result that more of the calories we eat get stored as fat. If this insulin resistance progresses unchecked, type 2 diabetes is the endgame.
2. Heart disease
Last year, one group of European researchers went so far as to declare that “the way to a man’s heart is through his gut microbiome.” There are a number of ways gut bacteria and heart health are linked. That inflammation-driven insulin resistance can keep levels of blood sugar elevated and encourage weight gain, both of which are bad for the heart. In some studies, giving subjects probiotic supplements actually reduced the levels of “bad” LDL cholesterol, which can contribute to heart disease and heart attacks. Sometimes the food we eat can interact with “bad bacteria” to create compounds that can damage the heart.
That was the finding from a study out of the Cleveland Clinic that found that subjects who regularly ate a lot of meat housed bacteria that turned some of the nutrients in meat into a toxic compound that encouraged the build-up of potentially dangerous plaque inside the arteries. On the bright side, the phytonutrients in foods like berries, green tea, and turmeric are superfoods for the “good” bacteria which may be one big reason why eating them can protect against heart disease and cancer.
We know in a general way that inflammation, of the sort that an out-of-balance gut can generate, helps drive cancer. And specifically, researchers have discovered that Africans, whose diet relies more heavily on plant food, have much lower rates of colon cancer than African-Americans who eat a meat and processed-food heavy diet. This Standard American Diet deprives the gut bacteria of the fiber it needs to protect the gut wall and prevent inflammation-provoking leaks.
New research is pointing to a link with prostate cancer. People with prostate cancer have bacteria in their urine and prostatic fluids that looks different than what’s in people who don’t have the cancer. It seems likely that a prostate infection may have killed off good, protective bacteria contributing to the growth of the cancer. Stomach and gastric cancers are on the radar as well. People who eat a lot of processed meat are at higher risk here. The nitrite preservatives in these meats combine with the gut bacteria to produce potentially carcinogenic compounds.
4. Irritable bowel syndrome (IBS)
Some common foods can overfeed an out-of-balance microbiome. The result? Gas, bloating, diarrhea, or constipation. It’s a whole laundry list of unpleasant digestive symptoms that get lumped together as IBS. The best solution is to eliminate foods from your diet, one by one, to see which ones are causing the problem. A great place to start are the gluten-containing grains, especially wheat and lactose-laden dairy products.
Some of the common offenders are healthy foods – vegetables like asparagus and onions and legumes like black beans – that are simply too much for the sensitive gut. You’ll probably be able to slowly re-introduce them into your diet as your gut becomes more resilient. And some of these IBS-offenders are food or food ingredients that we’d all be better off without, like high-fructose corn syrup and sugar-free gums and candies containing sorbitol and other sugar alcohols
The gut is intimately connected with the brain and there’s a growing body of research that suggests that when we take care of the bacteria in our guts we can lift our mood. Some of this work has been done on rodents – when researchers took gut bacteria from assertive mice and transplanted it into timid mice, they quickly got more feisty! But we have some very suggestive human studies as well. In one, a group of volunteers scored lower on anxiety and stressful feelings after they had been taking a probiotic supplement for two weeks.
The gut has its own nervous system, the enteric nervous system. And the bacteria in the gut are involved in the production of the same neurochemicals, like dopamine, serotonin, and GABA, which the brain makes to regulate how we feel and behave. How exactly the gut “talks” to the brain is still being worked out, but it’s fair to say that if you’re eating plenty of fiber-rich foods, and fermented foods, nature’s probiotic supplements, you’re taking out low-cost mental health insurance.