Take It In: Gut bugs likely control health, how we age

Sep 22, 2018 by Carol Bareuther

Take It In: by Carol Bareuther

Many foods, foods we eat every day, are teeming with microorganisms such as bacteria. Millions per mouthful, such as Lactobacillus bulgaricus, in the case of live culture yogurt. What’s more, our digestive tracts are full of these little bugs, too.

Scientists call this environment the gut flora, or gut microbiota. Preliminary findings of the American Gut Project, a massive citizen science project led by researchers at the University of California, San Diego, have found that gut bacteria – how many and what kind – are possibly linked to everything from good health to chronic diseases and even aging.

Probiotics, or ‘good bugs,’ are live microorganisms that provide a health benefit when enough are eaten. Probiotic bacteria work synergistically with the natural bugs living in the digestive tract to either get us healthy or keep us that way. Probiotics are especially helpful during times that the digestive system is thrown for a loop, like when taking antibiotics, when traveling disrupts our usual diet, or when not eating a healthy diet in general.

There are many different types of probiotic bacteria, each with its own strengths. For example, Danish researchers reviewed several studies and published a journal report last year highlighting Lactobacillus rhamnosus and Saccharomyces boulardii as the best at preventing the diarrhea that comes when taking prescribed antibiotics.

The probiotic bacteria mentioned above, plus others, are in many foods found at the supermarket, as well as in product formulations on the pharmacy shelves. There are two schools of thought regarding which is best. Some think that while food often doesn’t have the same amount of a probiotic per serving as a supplement, the benefit is a holistic mix of vitamins, minerals, dietary fiber, phytonutrients and the probiotic, which may provide more overall help than the probiotic bacteria alone.

Others think it’s best to take a supplement to change the ratio of good to bad gut bacteria quickly.

The best of both worlds may be to start with a supplement, then follow with a regular intake of probiotic-containing foods.

Yogurt labeled as having live cultures is an excellent source of probiotics. So are fermented foods. One of these is kefir, a milk drink with several strains of good bacteria. Researchers writing in the Brazilian Journal of Microbiology in 2013 tout kefir as an even better probiotic than yogurt. Smoothies, salad dressings and dips are a good way to consume kefir. Sauerkraut (look for unpasteurized to get live bacteria), kimchi, and pickles (but not those packed in vinegar, which can kill bacteria) are other probiotic foods.

Bad bugs are bacteria that either by type or quantity cause foodborne illness. Forty-eight million people annually get sick from foodborne illness in the U.S. alone. Salmonella, clostridium perfringens, campylobacter and staphylococcus aureus are among the bacteria most likely to cause foodborne illness. Produce – including fruit, nuts, mushrooms, leafy greens, root vegetables and sprouts – account for almost half of foodborne illness, according to the Centers for Disease Control in Atlanta, Georgia. Beef, game, pork and poultry account for another 29 percent.

While research reported in a  2016-published article in the journal of Applied Microbiology and Biotechnology suggests that good bugs may help fight bad bugs – probiotics such as those found in yogurt, for example, can protect against traveler’s diarrhea – better yet is to keep bad bugs out of foods so that the good bugs in probiotics can work towards wellness rather than preventing sickness.

Carol Bareuther is a registered dietitian and freelance health and nutrition writer. Comments are welcome below.


  • Clean foods well, especially fresh produce.
  • Separate raw and cooked foods.
  • Cook foods to the proper temperature.
  • Chill foods promptly so bacteria don’t have a chance to multiply.

Source:  U.S. Department of Health & Human Services