How to Feed Your Lower Gut: Microbiome Part II

In our previous post, we had outlined how your skin, mouth, and gut are hosts to trillions of mostly helpful micro-organisms:  bacteria, viruses, and fungi, which are vital to your health. For details, visit http://goo.gl/gsdJNe.

Research into these organisms is still in an early state. But we are getting a lot of useful insights.

Antibiotics hurt the good bugs, too

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In the first two years of life, an average American child receives almost three antibiotic courses. The next eight years bring eight more.

In 2010, almost every US citizen received an antibiotic course: doctors wrote prescriptions for 258 million antibiotic courses. It is quite clear that all of these were not prescribed for bacterial infections. Many infections suspected to be bacterial are due to viruses. Giving an antibiotic in this setting promotes resistance to antibiotics.

Such unnecessary antibiotic treatment also hurts the good bacteria in our intestines. Even necessary antibiotics end up killing both bad and good bacteria.

Antibiotics and chronic disease?

There is a school of thought which believes that antibiotic use and abuse in children, by disrupting their protective gut microbial environment, leads to an increase in chronic diseases like obesity, asthma, celiac disease, and type 1 diabetes. And these diseases are becoming more prevalent. Of course, more research is needed to prove conclusive linkage, but the signs are worrisome.

Gut bacteria, antibiotics and obesity

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Research on mice has led to the suspicion that antibiotics potentiate the effects of a high-fat diet in promoting obesity (? by eliminating useful gut bacteria). Mice placed on a high-fat diet become fat. However, mice given antibiotics early in life also tended to become obese, in a previous study. Finally, another group of mice which received antibiotics and a high-fat diet developed morbid obesity.

Again, more research is necessary, but it is clear that we need to be cautious and use antibiotics wisely.

Antibiotics to animals

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Farmers seem to have been aware of the link between antibiotics and body weight. Farm animals have been getting antibiotics for several decades, apparently to cut down the risk of infection, or to treat infections. However, in many cases, the dose of antibiotics used is lower than what is known to be effective for treatment of infections. It is possible that this lower-than-necessary dose of antibiotics may be directed towards making the animals more bulky. Animals tend to bulk up more rapidly if they are given antibiotics with food.

More research in this field will be needed to come to firm conclusions, but can we afford to ignore the warning signs?

Caesarian section and gut bacteria

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The baby prior to birth is surrounded by membranes which rupture during passage through the birth canal. At this point, the baby is exposed to the “good” bacteria in the mother’s body. These bacteria are swallowed, and also go to reside on the skin. This exposure starts the baby on a pathway to health through co-existence with healthy microbes.

Caesarian section obviously deprives the baby of this beneficial exposure. In addition, antibiotics used during this surgery also affect the baby’s bacterial environment.

Thus the gut microbes of babies born naturally and those born by Caesarian section are quite different. Does this have implications for their health? Many studies have looked at weight problems and the mode of birth. Pooling together multiple studies shows that being overweight as adults is 26% more likely to happen to babies born by Caesarian section versus those delivered normally. And obesity as adults is 22% more likely in Caesarian section babies.

Mother’s milk & complex carbs

Mother’s milk has nutrients for both the baby and its bacteria. Oligosaccharides (a type of complex carbohydrate) in this milk are not meant for the baby, which cannot even digest them. However, an organism called bifidobacterium infantis, present in the baby’s gut, can digest this nutrient, and uses it to proliferate in the gut. This is done at the expense of more harmful bacteria, which are crowded out.

There is an additional benefit: This microbe keeps the lining of the baby’s intestine healthy!

Stress and mood?

Let us look at mice again. If you take anxious and timid mice, and transplant into their guts the microbes from adventurous mice, the timid ones become adventurous! Obviously, we are not mice, but…

H. pylori, ulcers & obesity?

Many years ago, the bacterium Helicobacter pylori was shown to be responsible for stomach ulcers. Since then, doctors have been trying to eliminate it from Western stomachs, though people from other parts of the world still have it.

There is some suggestion, though, that H. pylori can calm the immune system, possibly leading to allergy and asthma being less common in communities which still have H. pylori.

Another possible effect: an empty stomach produces the appetite hormone, ghrelin, and you eat. When you are full, the stomach stops producing ghrelin, a signal is sent to the brain that you are full, and you stop eating. Data suggest that H. pylori regulates the amount of ghrelin produced by the stomach, and thus may have a role in causing or preventing obesity.

All of this is based on preliminary observations, and more research needs to be done. But eliminating or changing gut bacteria can have unintended consequences.

Gut bacteria, fermentation, and inflammation

The large intestine is vital for our health. The processed or ready-made food we eat nowadays is often digested and absorbed by the upper gut, leaving the large bowel with little to do.

The lining of the large gut is kept healthy by our gut bacteria.  If we eat a wide variety of plant fiber, this is fermented by the bacteria in the colon. As a result, short chain fatty acids are produced, which protect the health of the lining of the gut.

In the absence of this nutrient, the gut lining becomes leaky, and allows dangerous substances to be absorbed and enter the blood stream. The body mounts a response, and the result may be a low-grade inflammation. Some authorities feel this is the foundation for many chronic diseases common today.

Processed food

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Some processed foods have emulsifiers and other products which are suspected of damaging the lining of our guts, again causing leakage and inflammation.

So what to do?

There is not enough information available at present to prove cause and effect. More research is essential. But taking some common-sense measures might not be a bad idea.

  • Let us feed the lower gut with fermented foods, such as yogurt, kimchi, and sauerkraut.zaziki-368163_1280
  • Eat lots of plant foods with different kinds of fiber. Insoluble fiber in whole grains, resistant starch in oats, beans, and bananas, and soluble fiber in nuts and root vegetables like onions, will encourage fermentation by large gut bacteria, with resulting health benefits.
  • Raw or lightly cooked vegetables are better for the gut flora.
  • Exercise regularly: preliminary data suggest that this creates a more hospitable gut environment for “good” bacteria.
  • Use antibiotics wisely.
  • Don’t overuse hand sanitizers. You might eliminate “good” bacteria, too.
  • Work with soil! Digging around in your vegetable patch will expose you to a variety of useful organisms.
  • Try to avoid processed foods.
  • Prebiotics, probiotics, and all that jazz: this is a vast industry, promising you the moon. Regulation of this industry does not appear to be very strict. Products available contain huge quantities of microbes, of which lactobacillus and bifidobacterium seem to be useful for our immunity. However, at least one study has cast doubt on whether you always get the microbes which the labels mention.

Too much info?

Possibly. Not too much proof is available yet. However, we often have to make decisions and judgments in real life, based on incomplete evidence.

So use common sense, while trying to get ahead of the curve!

 

 

2 thoughts on “How to Feed Your Lower Gut: Microbiome Part II”

  1. good advice and interesting information. I did not know that about c section babies. look forward to the next article.

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