Not all probiotics are the same. In fact, there are plenty of different strains, and some may have different potential health benefits than others. Although not a cure-all, there is good reason to consider adding probiotics to your diet, either in food or supplement form.
A healthier heart
Probiotics are live micro-organisms, gutfriendly bacteria that are found in yoghurt, fermented foods, aged cheeses and supplements. A 2017 review of 15 studies published in PLoS One found that taking the probiotic Lactobacillus could reduce LDL or ‘bad’ cholesterol. One way the bacteria can reduce blood lipids is through an enzyme, bile salt hydrolase, according to Professor Mary Ellen Sanders, executive science officer of the International Scientific Association for Probiotics and Prebiotics.
“Bile salts are precursors to cholesterol, and gut microbiota can impact bile salt levels,” she says. Dietitian Tanya Zuckerbrot, bestselling author and founder of The F-Factor Diet, says the bacteria utilise cholesterol as they grow in the gut. “The more bacterial cells that grow and divide, the more cholesterol is required to stabilise their cell membranes, which can contribute to an overall cholesterol-lowering effect,” she says.
Good bacteria may be among the most trusted home remedies for natural anxiety relief. In a meta-analysis of ten controlled trials published in Neuropsychiatry, researchers found that probiotics decrease the symptoms of anxiety and stress in people with anxiety compared with control groups. “Many neurotransmitters that regulate mood, like serotonin, are located in the gut,” says Dr Frank Lipman, bestselling author of How to Be Well. “If your gut is healthy it can help keep anxiety at bay.” The gut is connected directly to the brain via the vagus nerve, Professor Sanders explains, so what goes on in the gut can be transmitted to the brain.
A 2017 review of research on probiotics and oral health suggested they could be beneficial for maintaining oral health, but more research is needed to find the dosage and specific bacterial strains that work. Some previous research found that Lactobacillus and Bifidobacterium can reduce some strains of harmful bacteria that cause gum disease.
They may also “decrease cavities in kids, especially in ages three to four,” says family doctor Dr Angela U. Tucker. Other research from the American Society of Microbiology found that good bacteria help neutralise enamel-destroying acid in your mouth
Fewer colds and coughs
Yoghurt – or the probiotics it contains – is one of the immunity-boosting foods that may help fight off colds and flu. Dr Lipman says that 70 per cent of our immune system is housed in our gut, which is why it’s so important for overall health. According to Zuckerbrot, beneficial bacteria create an acidic environment that’s inhospitable to harmful bacteria. In addition, good bacteria can have a major impact on the lymphatic system, an important part of our immune function. “
Certain [good bacteria] can help to stabilise the lining of the gut where the lymph tissue resides and prevent harmful substances from being absorbed,” Dr Tucker says.
Reducing allergies and eczema
The gut may also influence other inflammatory, autoimmune or allergic reactions, including eczema. “Most of the data concerning prevention of allergic conditions have been found for infants and children,” Dr Tucker says. “Studies showed decreased chances of eczema in children born to breastfeeding mums who received probiotics for the last four weeks of pregnancy and through the first three months of life.” Another 2017 study in the American Journal of Clinical Nutrition found that a certain bacterial combination reduced seasonal allergies, however the “mechanism to show how they curb allergy symptoms has yet to be determined,” Zuckerbrot says.
In general, Dr Lipman says good gut bacteria can help your body manage its immune responses. “When your immune system is working properly it helps create proper checks and balances against perceived threats,” he says. “If your gut – and therefore your immune system – is out of balance, it may mistakenly overreact to things like food and the environment. Keeping your gut healthy will support proper checks and balances.”
Combating the effects of antibiotics
Do you really need to take a probiotic after antibiotics? Antibiotics can wipe out the good bacteria as well as the bad, wreaking havoc on your gut. A review found that using probiotics helped reduce the risk of antibiotic-associated diarrhoea by 51 per cent. “Taking antibiotics can disrupt the normal protective microbiome, and it typically takes six to eight weeks for normal microbiota to recover after antibiotic exposure,” Zuckerbrot says. “S. boulardii acts as temporary protective microflora until full recovery of the microbiome is achieved.”
Preventing vaginal infections
As many as 30 per cent of women may experience an infection called bacterial vaginosis (BV) at some point in their lives and they may not even know it. Bacterial vaginosis happens when the vagina’s special mix of healthy bacteria is disrupted. “Bacterial vaginosis can be treated by oral or vaginal application of probiotics,” Dr Tucker says. “The Lactobacilli increased microflora’s return to normal, resolving the BV. Although not as effective as an antibiotic, they’re still found to be better than acetic acid or placebo.” But, their effectiveness in treating yeast infections is limited. “It can be considered though for people who have recurrent yeast infections or those unable to take first-line therapies,” she says.