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Good eating habits and the role of probiotics

A diet which contains a variety of nutrients which helps a diversity of gut bacteria thrive is essential for good health

Consuming plenty of foods rich in prebiotic fibres, such as fruit, vegetables and whole grains, as well as probiotic-rich foods that are fermented such as miso, yogurt and pickles can help keep the gut in good health.

FOR most people the word "bacteria" conjures up the image of pathogenic germ-causing harm to the human body. In fact, human beings have been battling bacteria for a long time, which have emerged to be smarter with the appearance of multidrug-resistant strains.

However, our bodies actually host trillions of micro-organisms, most of which stay in our intestines. In fact, they outnumber our body's cells to the extent of a 10-to-1 ratio.

The gut bacteria are friends to our bodies and they play an important role in our digestive and metabolic processes. Some bacteria are necessary in the production of vitamins including vitamin K and folate, and also aid in the digestion and absorption of nutrients. Their functions are not just confined to the gut. The gut micro-organisms also stimulate and enhance our immune functions.

When our digestive tracts are affected by poor eating habits, taking medication such as antibiotics, the gut flora gets disrupted. This can create a variety of problems, ranging from abdominal symptoms such as bloating, diarrhoea and constipation to other conditions such as weight gain, diabetes mellitus and skin eczema.

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Studies have shown that probiotics which contain "good bacteria" can help to maintain or restore the healthy pool of friendly bacteria in our bodies. This work can be traced as far back to the early 1900s, during which time the Nobel Prize-winning scientist Elie Metchnikoff isolated lactic acid-producing bacteria from sour milk (yogurt) and attributed the longevity of Bulgarian peasants to their yogurt consumption.

Most research of probiotics nowadays covers two main species: lactobacillus and bifidobacterium. They work by changing the composition of our gut bacteria. They may produce enzymes or proteins that control the population of harmful bacteria. They also aid in digestion and improve nutrient absorption, and can improve lactose intolerance by breaking down lactose into nutrients that the body can use.

In view of the benefits of probiotics, more people are taking it now as a health supplement. This has placed probiotics as the second most common health supplement consumed after the vitamins.

In fact, the rapid growth in probiotics use has outpaced scientific research on the benefits. There are conditions for which people take probiotics with little evidence to support that practice.

Although probiotics are generally safe to consume with minimal side effects, their use in people with weak immune systems needs to be prudent. As probiotics contain live bacteria, there were previous reports of probiotics-related severe infections in those with immuno-compromised conditions, although this is not common.

Generally speaking, the evidence is not yet conclusive on its use as disease prevention in healthy individuals. This group of people do not need to take probiotic supplements to improve their gastrointestinal health. Instead, they can modify their diet and lifestyle which can directly or indirectly maintain the good bacterial balance in the digestive system.

  • Many food sources contain probiotics. Consume more cultured milk such as yogurt and fermented vegetable products such as sauerkraut, pickles, kimchi and miso which have naturally occurring probiotics;
  • A diverse gut microbiota is considered to be a healthy one. There are hundreds of species of bacteria in our intestines and each requires different nutrients for growth. Unfortunately, our diets are not diverse enough and contain mainly fat and sugar. Hence, changing our diet by consuming different food types can provide our gut with a variety of nutrients that help promote a diversity of microbiota;
  • Eat plenty of foods which are rich in prebiotic fibres, such as fruit, vegetables and whole grains. Prebiotics (not probiotics) are a type a fibre which can't be digested by our bodies, but can be digested by certain bacteria in our gut, which in turn stimulate their growth;
  • Have enough rest and avoid excessive alcohol consumption, as poor sleep quality and excessive alcohol consumption can harm our gut bacteria;
  • Red wine, through its polyphenol content, can increase the abundance of bacteria and decrease the number of harmful gut bacteria;
  • Avoid taking antibiotics as it is certainly true that they can affect both the good and bad bacteria and lead to harmful changes in the diversity and composition of the gut flora.

Who needs probiotic supplements?

So far, studies are not yet conclusive on probiotic use on healthy people. Hence, it should only be used in certain conditions in which the probiotics are proven to be helpful for.

In digestive disease, probiotics have been shown to improve symptoms of irritable bowel syndrome such as bloating, constipation and diarrhea and it also helps in the recovery from an intestinal infection.

Do I need to care about the probiotic strain?

It is important to know which probiotic strains are contained in the products as they are not a "one strain fits all" proposition. Different strains work for different health conditions.

It is best to use only the strain which has been shown to be effective in clinical trials in the treatment of the specific condition or the symptom you are looking to ameliorate. One study in irritable bowel syndrome showed that a particular strain of probiotics improved constipation but didn't have much effect on the abdominal pain or discomfort. Therefore, choosing the right type of probiotics is essential especially those that have demonstrated the therapeutic efficacy.

The same cannot be said for other products even when they have similar strains as the studied probiotics, as they can have significantly different therapeutic actions, properties and characteristics. Always consult your doctors on the probiotics which are suitable for you.

Many probiotic supplements also combine different species and strains together in the same supplement as a combination of probiotics is usually more effective than a single one.

Do I need billions of bacteria in the probiotics?

As a consumer, it is easy to be influenced by the sales pitch of a brand boasting the amount of probiotics in their products. However, this does not paint the whole picture.

Probiotics are live bacteria, its effectiveness and viability depend on how well the bacteria are able to stand up to the acidic environment of the stomach as well as the manufacturing processes such as compression and heat.

The quantity of bacteria in the supplement is measured in colony-forming units called CFUs. Higher CFUs will stand them a better chance to reach the intestines after overcoming the negative factors.

However, certain strains of bacteria are strong and resilient and able to survive the trip through the pH-barrier of upper gastrointestinal tract better. Other bacteria produce spore and some products have special protective coating for the probiotics, all of these can protect the bacteria against the acidity in the stomach.

Hence, some probiotics may be effective at dosages of 100 million CFUs per day, while others may require at least 20 billion CFUs to achieve the desired effects.

It is more important to buy a probiotic supplement that has an independent survey of the viability of the product and also has proven efficacy of the therapeutic purposes.

Overall, probiotics have a short shelf life. Always check the expiration date on the label in order to make sure there are adequate amounts of viable organisms contained in the product at the time of consumption.

Do I need to take probiotics for the long term?

Probiotics do not permanently colonise the intestines in most cases. They are just to facilitate a healthy environment in our bowels to maintain a pool of friendly bacteria. It is advisable to take daily doses of probiotics if it works for your condition.

However, not everyone responds even to the same probiotics. If it doesn't work for you after taking it for a short period like 30 days, you can consider discontinuing it.

This series is produced on alternate Saturdays in collaboration with Singapore Medical Specialists Centre.