Probiotics are live friendly microorganisms that maintain the balance of gut flora when consumed in adequate quantities. They confer upon us a bounty of health benefits like aiding digestion (especially in case of lactose intolerance), boosting immunity, preventing/treating vaginal as well as urinary tract infections and eczema in children. But probiotics are specific in action viz., their effect may vary between species or even between different preparations of the same species. Their intake is often advised along with a strong dose of antibiotics. The latter destroy the beneficial microbes in the gut along with pathogens and hence the prescription to restore the good microbes.
Ask anybody to name a probiotic food and pat comes the answer, “yoghurt”. If a few choose to differ in their reply, they trail away only as far as “buttermilk”, “probiotic milk” or “probiotic ice creams”. On hearing dairy products for an answer so many times, it is easy to perceive that those are the ones that are commonly available and people are informed about. So, are there any probiotics beyond dairy products? Oh yes, there are quite a lot. Most of the fermented foods are rich in probiotics. A few of them from around the world are as follows:
- Miso: This is a popular Japanese seasoning made from fermented rice, barley, rye and/or soyabeans (the main ingredient in the most common type of miso), salt and the fungus Aspergillus oryzae (colloquially known as Koji fungus). A small quantity of this is usually added to hot water to prepare a probiotic-rich Miso soup.
- Tempeh: This is an Indonesian tofu–like soy cake. This is prepared by processing whole soyabeans and fermenting it by Rhizopus oligosporus starter. Though soy tempeh is the most common, there are other varieties made from coconut, peanuts, food grains and some pulses.
- Sauerkraut: This is fermented cabbage that is rich in Lactobacillus acidophilus.
- Kimchi: This is a Korean side dish that is a close cousin of sauerkraut. In addition to fermented cabbage, it also contains other vegetables like radish and cucumber. It is highly spicy. Central American Cortido and French Choucroute are also other forms of fermented cabbages rich in probiotics.
- Brine cured olives: These contain high levels of Lactobacilli. It should however be borne in mind that addition of preservative sodium benzoate or pasteurization done to extend shelf-life in commercially sold sauerkraut, kimchi and brine cured olives, will destroy the probiotics.
- Kambucha tea: This is an effervescent fermented tea prepared from SCOBY (Symbiotic Culture of Bacteria and Yeast). SCOBY is also referred to as mushroom or mother of vinegar. SCOBY usually contains Acetobacter bacteria and one or more yeasts.
A consumer should look for tags like “live”, “raw”, “cultured” and “live and active cultures” while purchasing them from shops; other pertinent info that would be helpful are details regarding the strain of microbe in the food, its shelf-life, viability and appropriate storage methods. Probiotics are not only found in foods but are also sold as capsules and powders. But, I loathe the idea of swallowing pills for meals. It is always a fulfilling experience to relish food and simultaneously derive the goodness from it, rather than replacing it with tablets. Of course, the pills have a purpose…they are for people with erratic eating habits, invalids who are in an emergency situation to get the benefits by popping pills. Leave the pills to them and get your probiotics, also from the array of natural foods besides milk products.
Can Probiotics Be Stress-busters?
A recent study considered a breakthrough in probiotics research suggested that probiotics could reduce anxiety and depression in mice. A summary of the study published in the Proceedings of the National Academy of Sciences is as follows:
John Cryan, a neuroscientist at University College Cork in Ireland and his team fed a strain of Lactobacillus rhamnosus JB-1 to a group of healthy mice (Experimental Group or EG) and a bacteria-free broth to another (Control Group or CG) for 6 weeks. L.rhamnosus is a species found in some yoghurts and the dose was roughly the same amount claimed to be in a pot of Actimel yoghurt. The mice were subjected to a series of stress tests. In negotiating a maze, the EG exhibited less anxiety compared to CG by venturing out into open spaces more often. In the forced swim test also, the EG performed better than the CG by fighting it out rather than giving up. The researchers found that:
- Post swim test, the level of stress hormone corticosterone in the blood of EG was just half of that in the CG.
- The brain receptors for the neurotransmitter GABA in EG were redistributed in a pattern common in non-depressed animals.
- These probiotics produced effects in EG tantamount to anti-depressant drugs.
- These effects were manifested as long as the vagus nerve – the main link between the gut and brain remained intact. Once it was snipped off, there was no difference between the 2 groups.
The researchers concluded that this particular strain of probiotics definitely impacted the chemistry of mice brain in a positive way; they alleviated stress and anxiety in mice. Whether the results can be extrapolated to human beings remains to be seen. Emeran Mayer, a gastroenterologist at the University of California, Los Angeles is skeptical about the findings translating easily from mice to people. He says, “Personally, I think human emotional behavior is much more complex, so I don’t think you’ll ever find these kinds of dramatic responses.” Mark Lyte, a microbial endocrinologist at the Texas Tech University Health Sciences Center in Abilene says, “It MAY, in really big capitals, prove to be an adjunct to therapy, but there are a number of steps that need to be done.” So, if at all this is proved true in human trials as well, then probiotics may emerge as the most sought after foods in today’s stress driven world.