The Right Germs: Gut Bacteria and Diabetes

Type 2 diabetes tends to run in families: If parents have it, children are likely to get it too. But is that because of having similar genes, or similar behaviors? Maybe it’s neither. Maybe it’s having the same kind of bacteria in their guts.


This is an exciting idea, because if we find a way to change gut bacteria, we might be able to cure diabetes. The right germs have cured several other diseases, so why not diabetes?

What’s the evidence for a bacteria/diabetes connection? A Swedish study of 145 women found that the genes in intestinal bacteria predict diabetes more accurately than waist-to-hip ratio or body-mass index (a measure of weight relative to height).

A Chinese study of 345 people published last year found the same thing. The authors wrote,

Analysis showed that patients with Type 2 diabetes were characterized by…a decrease in some…butyrate-producing bacteria and an increase in various opportunistic pathogens.

According to scientists at the University of Aberdeen, “Butyrate plays a key role in maintaining human gut health, as the major source of energy to the colonic mucosa.” Butyrate also seems to prevent inflammation and cell death.

Our resident bacteria are called our microbiome. The combination of our own genes and those of our resident bacterial is called our metagenome. A disordered metagenome has been linked to obesity as well as diabetes. A study of female twins from Missouri showed that obese women had different bacteria in their guts than leaner women. They had a “lower proportion of Bacteroidetes and a higher proportion of Actinobacteria.”

I don’t know what that means, except that Bacteroidetes are normal and needed in the large gut. Actinobacteria are normal, too, but they cause a number of diseases. It seems that having more of the right bacteria and less of the bad ones may be as important to health as genes or diet.

Curing diseases with germs
Germs are being used or studied for curing diseases including cancer, ulcerative colitis, constipation, and multiple sclerosis, among others.

You may have heard of the very hard to cure toenail fungus called tinea. It’s basically athlete’s foot fungus that gets under the nail where creams and sprays can’t reach it. The oral drugs given for it are toxic to the liver and work less than half the time. People wind up never showing their feet in public again.

But according to some alternative practitioners, another fungus, Pythium oligandrum — sometimes called the Vampire Fungus — usually eats the tinea up, and then dies off. You put Vampire Fungus spores in your socks for a couple of days and your feet are free!

I admit I’m prejudiced. I like germs. As I’ve written about several times, the bacteria in our large intestine digest fiber and provide energy in the form of short-chain fatty acids, or SCFAs. SCFAs have lots of beneficial effects against diabetes and perhaps other diseases. Fiber is good because it feeds the good bacteria, producing more SCFAs.

How to get the right bacteria? Some foods might promote good germs. In an article about probiotics, our nutritionist Amy Campbell provided a list of the relatively few foods that provide good bacteria. These include sauerkraut and kimchi (fermented cabbage and spices), tempeh, aged cheeses (Gouda, Cheddar, Emmental, blue cheese), and yogurt with “live cultures.”

Those are good, but the acid in our stomachs may kill the germs before they get to the large intestine. And they may not be the best kind of germs anyway. There is another way.

Warning: This gets icky

Instead of eating good germs, you can have them inserted directly into your colon with an enema, a process called fecal microbiota transplant, or FMT. The Web site Power of Poo is devoted to people who recovered from severe ulcerative colitis with FMT. This “incurable” disease is usually treated ineffectively with steroids or with surgical removal of the colon. But apparently it can usually be cured with the right germs.

FMT seems to be an almost certain cure for infection with the nasty bacterium Clostridium difficile (C. diff). C. diff kills thousands of people each year. Antibiotics don’t work well against it, because antibiotics cause it. They kill all the good germs and let the C. diff run wild. But if you put good bacteria back in, they take care of the C. diff in a matter of days.

FMT frequently cures constipation. Very exciting to me is one constipation study that enrolled among its 15 subjects three patients with multiple sclerosis (MS). Each of the three not only recovered normal bowel function, but got out of their wheelchairs and, in at least one of the cases, is still walking unaided 15 years later.

I may have to try this, but there are some downsides. Obviously, it’s icky. It’s hard to find someone to do it for you, and it’s not covered by insurance, so you may have to do it yourself. This means finding the right donor and dealing with a lot of ick. Still, it might be worth it.

Can fecal transplant treat Type 2 diabetes? I wouldn’t be surprised. It’s being studied in China. In another study, FMT was found to reduce insulin resistance in 18 Dutch women studied.

Unfortunately, the FMT industry doesn’t have the resources of the drug industry. Actually, there is no FMT industry. So we’ll see if more research is done. If you are interested, you can find out more here. Or at least consider eating some probiotics.

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  • Kathleen

    David, This is so interesting. Reading (or trying to read and understand all the science) that was in the documentation listed led me to believe that there may be foods that will promote the growth of butyrate, like white carbs. Oh wow eating white food again would seem so counterproductive.

    We live in a marvelous world where germs and bacteria may be a cure for disease. And I can go back to eating pancakes and scones. (Not really)

    It is noteworthy that a few months back I read a post by you about adding vinegar to our diets to help with high blood sugar. Kimchi has lots of vingegar. Well I hope some curios people do more study on this subject.

  • jim snell

    neat. Great work David. extremely interesting data. Put real science to work not pre conceived notions.

    As always our blessings and thanks.

  • Joe

    Another fine article, David.

    Per the link to Amy Campbell’s post on probiotics, I plan to try out Saccharomyces boulardii, a probiotic fungus that shows promise in fighting Clostridium difficile. Note, I’m going to use the capsules. Not ready for fecal microbiota transplant at this point. ūüôā (Although I think I could handle the ick factor… where would I find a donor?)

  • Gail Campbell

    are you sure you got your intestinal bugs right? I’m familiar with Bacteroides, but have never heard of Bacteroidetes (and I’ve worked as a medical transcriptionist over 30 years, so I’ve got to know many medical words). Clostridium difficile and Actinobacter are some of our common intestinal creatures that help us deal with the inner world.
    Fecal transplant sounds promising.

  • Joe

    Follow-up on using Saccharomyces boulardii to fight IBS and a potential case of bacterial overgrowth. Ten days after being on S. boulardii and I’ve noticed a stabilization in bowel function after several months of persistent issues. Last night as a test I ate a food that generally gives me fits, and rather than the usual reaction I had only moderate bloating and gas. The constant nausea has eased significantly. So far, so good. I visited my Internist yesterday and he advised me to continue the therapy and monitor. As an aside, I had the lowest BP reading I’ve registered in several years, 117/72. Not convinced it’s related, but S. boulardii is reputed to have an anti-inflammatory affect, so who knows?

  • David Spero RN

    Thanks for keeping us posted, Joe. Glad it’s going well.

  • youcrankypants

    Not diabetic, and not a doctor. However, I had frequent bouts of IBS and constant acid reflux. Started on the Kombucha path. No more IBS, down to taking one Ompeprozole every 3 days as maintenance, vs. daily. Now make my own Kombucha (so about 25 cents a day vs. $3-4). Highly recommend it, but do check with your doctor first. Less risky is the organic vinegar, and other fermented foods like sauerkraut, kimchi, pickles, but there is a sodium issue for many people.