Friendly Microbes in Our Gut

▲ We are only ten-percent humans ▲

In terms of cells, we are only ten-percent humans. Ninety percent of the cells in our body are non-human microbial cells.

Gastrointestinal tract, which starts from the mouth and ends in the anus, is the living place of at least 500 different species of bacteria amounting to the total number of up to 200 trillion, which is ten times as many as human cells. Those bacteria are called Gut Microbiome or Gut Microbiota or Gut Flora.

Residing mainly from duodenum onwards, those microbes are basically categorized into friendly bacteria (Probiotics) and harmful bacteria (Pathogens). Lactobacillus, the bacteria found in yogurt, and Bifidobacteria, those having Y shape, are in the group of friendly bacteria. Among pathogens, there are Clostridium species, Klebsiella species, and many others.

▲ Take care of your gut and you will have no worry ▲

Dr Theodor Escherich discovered the presence of bacteria in our gut, in 1880. It was named after him as Escherica coli. From then on researchers found out one after another.

Nowadays, it is realized that these gut bacteria influence our health in many ways, from helping to extract energy out of food to building the body’s immune system, to protecting against infections. It is also shown that those gut flora influence body weight and lowers the risks of diabetes mellitus and heart disease.

The most attracting evidence is that the gut bacteria are connecting with the brain via gut-brain axis and having an effect on brain and behavior. The friendly bacteria are capable of stimulating intestinal cells to secrete ‘serotonin’. Serotonin is the ‘happy messenger’ for the brain, the deficiency of which is associated with anxiety and depression. It was published in a study that when volunteers followed a 30-day course of probiotic bacteria they experienced decreased anxiety and depression and alleviated psychological stress.

This finding is in accordance with a saying in Myanmar culture stating ‘If you take care of your gut, you will have no worry’.

▲ Unusual treatment for a diarrhea outbreak ▲

In 2003, North America and Europe had uncontrollable diarrhea outbreak due to Clostridium difficille (C.difficile) infection. C.difficile is one of the pathogens of gut flora, the growth of which is normally suppressed by friendly bacteria. However, when they become overpopulated diarrhea will result. This diarrhea was resistant to the treatment with usual antibiotics.

Physicians used an unusual treatment for the control. They used the fresh stool of a healthy person as the drug. Thirty to 100 grams of fresh stool that contains good bacteria was diluted 5 times with sterile water or normal saline. After preparation, the fecal suspension was given to the patient through nasogastric or nasoduodenal tubes. This treatment was named ‘Fecal Microbial Transplantation’ (FMT).

FMT was found to be efficient in the treatment of C.difficile infection with the cure rate as high as 90 percent. As a result, ‘Stool Banks’ emerged in United State, across Europe, and in Hong Kong.

Since then more and more researches were focused on health beneficial effect of gut flora.

▲ The ways the gut bacteria are helping us ▲

Our friendly bacteria in the gut play an important role in defending against pathogens by fully colonize the space, and by killing or inhibiting the harmful organism. In addition, they are preventing the actions of some bacteria that are causing obesity, cardiovascular disease, and diabetes mellitus.

Some bacteria readily convert the dietary carbohydrate into fats causing obesity. It was found out that when the gut flora of an obese person was transferred into mice, the mice became obese as well.

Some harmful bacteria release a compound called trimethylamine-N-oxide(TMAO) into the blood which is capable of increasing risk of heart disease 2.5 times.

However, the good bacteria secrete short-chain fatty acids into circulation, which increase the sensitivity of the action on Insulin hormone. Diabetes mellitus is the disease of poor action of Insulin on the cells.

Babies who are receiving breast feeding have well developed intestinal immune system as breast milk is the good source for growing healthy bacteria.

There are ways to keep our healthy gut bacteria

Having good friends is important not only for our social lives, but also in our gut, as gut bacteria are saying to us.

The commonest way of destroying healthy gut bacteria is the indiscriminate use of antibiotics. Overusing or frequent taking of antibiotics can kill off healthy ones and allow the overgrowth of unhealthy ones.

Lacking sound sleep and regular physical exercise are associated with a disturbance of healthy growth of bacteria. The habit of eating too many red meats, high fats and high sugar foods are also having the same effect. Spicy foods, by changing the acidity of the intestinal contents, provide a favorable condition for diarrhea-causing bacteria.

▲ There are some evidence-based ways to improve our gut bacteria ▲

1. Eating Probiotic Foods

Probiotics are foods that are rich in healthy bacteria. Yogurt contains Lactobacilli and fermented foods such as preserved soya bean biscuit (Pe Pote) and soya bean sauce (Pone Ye Gyi) are good sources of both Lactobacilli and Bifidobacteria.

2. Eating Prebiotic Foods

Prebiotics are foods that promote the growth of beneficial microbes in the gut. All kinds of fruits and vegetables are in this group.

3. Eating high fiber foods

Whole meal bread, brown rice, pulses and Quaker oats contain indigestible carbohydrate called fibers which are, though, good source of nutrients for healthy bacteria.

4. Breast feeding to new born for at least six month

The breast milk is not just an ideal nutrient for an infant, but also for the friendly bacteria inside the gut. Studies have shown that infants who are formula-fed have altered gut microbiome with fewer healthy bacteria.

5. Keep-up the healthy lifestyles

Enough sound sleep, regular physical exercise, and managing stress can all have a positive impact on the gut bacteria.

▲ Take home message ▲

The gut microbiome is extremely important for many aspects of health.

Many studies have shown that a disrupted microbiota can lead to numerous diseases.

The best way to maintain a healthy gut microbiome is to eat a range of fresh whole foods, mainly from plant sources like fruits, veggies, legumes, beans and pulse and, of course, to keep a healthy lifestyles.

References:

1. Gut flora. Wikpedia.

2. Role of the gut microbiota in nutrition and health. British Medical Journal. 2018; 361. k2179.

3. Intestinal microbiota, probiotic and mental health. Gut Patho. 2013 Mar 18;5(1)

4. Fecal microbiota transplant. Wikepedia.

5. Successful Fecal Microbiota Transplantation in a Patient with Severe Complicated Clostridium difficile Infection after Liver Transplantation. Case Report in Gastroenterology 2018;12:76-84

6. 10 Ways to improve Your Gut Bacteria, Based on Science. Healthline. https://www.healthline.com/nutrition/improve-gut-bacteria

By Professor Dr Maung