Probiotics: Beyond Digestion
The whole-body benefits of friendly bacteria.
Most people associate probiotics with better digestion, since probiotics are taken to supplement the bacteria that live in the gut. But as scientists continue to reveal the importance of a healthy microbiome on overall health, the benefits of probiotics have expanded well beyond digestion to include the following.
Behind digestion, immunity is the second most popular use of probiotics, since about 70 percent of the body’s total number of immune cells reside in the gut. The research is vast. One recent analysis examining 20 published trials concluded that Lactobacillus and Bifidobacterium probiotics can cut the duration and severity of cold symptoms and lead to fewer missed days at work or school.
Specifically, Swedish researchers in one large study found that Lactobacillus plantarum HEAL9 (DSM 15312) and Lactobacillus paracasei 8700:2 (DSM 13434) strains, given at 1 billion CFUs per day, can drop common cold symptoms by about two and a half days. Another study examined the effects of a three-strain probiotic blend (Lactobacillus helveticus Rosell-52, Bifidobacterium bifidum Rosell-71 and Bifidobacterium infantis Rosell-33) on kids’ sick days. Researchers found that just 25.8 percent of the children who took the probiotics had a sick day, whereas 42.8 percent of the children who did not take the probiotics missed school.
According to a double blind, randomized, controlled trial, the intake of probiotic bacteria Lactobacillus gasseri (PA 16/8), Bifidobacterium longum (SP 07/3) and B. bifidum (MF 20/5) for at least 3 months significantly shortened common cold episodes by almost 2 days and reduced the severity of symptoms.
Researchers know that overweight and thin people have very different gut bacteria populations, suggesting that bacteria may be a factor when it comes to obesity. In fact, when overweight people begin to lose weight, their gut bacteria starts to resemble that of thin people.
One probiotic strain in particular, Lactobacillus gasseri SBT2055, was found to promote the body’s excretion of fat during bowel movements, instead of absorbing it. Put to the test, a study among 30 healthy Japanese adults found that five billion CFUs daily for just one week was enough to start reducing belly fat and promoting weight loss. Another study showed that when 28 healthy but overweight participants ate yogurt containing both Lactobacillus fermentum and Lactobacillus amylovorus, all of them lost body fat. In fact, people who ate yogurt fortified with the L. amylovorus strain lost four percent body fat, a statistically significant figure, suggesting that gut microflora may increase metabolism.
Why? Researchers speculate that probiotics improve blood glucose and weight control by cooling inflammation and balancing the gut-derived hormones that regulate appetite.
The gut-brain axis is an emerging area of microbiome science, which suggests that the microbiota in the gut can impact what happens in the brain. According to one study, supplementing with probiotics can lead to less stress and anxiety, better memory and lower levels of cortisol in the morning. This research came on the heels of a British study that suggested that prebiotics may soothe anxiety.
Scientists speculate that the gut-brain axis is powered by the fact that gut cells make 90 percent of the body’s serotonin, along with other mood-enhancing neurotransmitters such as GABA, dopamine, adrenaline and noradrenaline.
The skin, like the rest of the body’s organs, depends on nutrients to achieve peak performance. So, it makes sense that an unbalanced digestive system, which can deprive the entire body of nutrients, can also lead to dull and problematic skin. The good news is that emerging research shows that probiotics may have a role to play in skin health.
One study randomized young women to receive either conventional yogurt or yogurt enhanced with Lactococcus lactis strain H61 for four weeks. Blood samples taken at the beginning and end of the trial measured skin hydration and elasticity, as well as sebum and melanin content. After four weeks, skin hydration among all women in the study increased. However, sebum content of the women who consumed the probiotic yogurt rose significantly, while the levels of the women who ate the conventional yogurt did not.
According to the American Heart Association, probiotics may help maintain healthy blood pressure, and according to the research, the positive effects from probiotics seemed to be greatest in those with elevated blood pressure. Researchers think that probiotics support healthy blood pressure levels by having other positive effects on health, like keeping cholesterol in check. Previous studies have shown that the probiotic strain L. reuteri, specifically, can support a healthy balance of good and bad cholesterol by breaking up bile salts.
This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.