Recommended Probiotics for Constipation
Summary: Several probiotic strains have been shown to provide relief from constipation in children and adults when taken alone or together.
Probiotics That Are Effective Against Diarrhea
Diarrhea is defined as loose-to-liquid bowel movements that occur more frequently than normal.
It is typically short-lived, but can become chronic in some people.
Probiotics have been found to reduce stool frequency in the infection-related diarrhea that occurs with food poisoning and gastroenteritis, commonly known as "stomach flu" (13).
A large review of 34 studies found that probiotics reduced the risk of diarrhea from various causes by 34%.
Effective strains included Lactobacillus rhamnosus GG, Lactobacillus acidophilus and Lactobacillus bulgaricus (14).
Antibiotic use is another common cause of diarrhea. When antibiotic therapy kills harmful bacteria that cause infection, beneficial bacteria are destroyed as well. The shift in bacterial balance can lead to inflammation and diarrhea.
A large review of 82 controlled studies found that taking probiotic supplements reduced the risk of developing antibiotic-associated diarrhea by 42%. However, the most effective probiotic strains weren't discussed (16).
Although some people with IBS struggle with constipation, others experience frequent episodes of diarrhea, which is known as diarrhea-predominant IBS.
Research suggests that certain probiotics seem to be especially effective for diarrhea-predominant IBS, including B. coagulans, S. boulardii and a combination of several Lactobacillus and Bifidobacterium strains (17, 18, 19, 20).
However, one study did not find any significant improvement in diarrhea among IBS patients who were treated with S. boulardii (21).
Recommended Probiotics for Diarrhea
Summary: Probiotic therapy has been shown help reduce the severity and frequency of diarrhea related to infection, antibiotic use and IBS, among other causes.
Probiotics That May Improve IBS Symptoms
Sometimes the main symptoms of IBS aren't related to stool consistency or frequency. Instead, some people experience bloating, gas, nausea and lower abdominal pain on a regular basis.
A review of 19 studies found that while some people reported improvement in IBS symptoms while taking probiotics, results varied between individuals. Researchers couldn't determine which probiotics were most effective (22).
In addition, because the symptoms of IBS are so diverse, sometimes one symptom improves while others do not.
For instance, one study of people with constipation-predominant IBS found that although S. cerevisiae improved constipation, it didn't have much of an effect on abdominal pain or discomfort (11).
In another study, participants with diarrhea-predominant IBS were given a supplement known as VSL#3, which contains Lactobacillus, Bifidobacterium and Streptococcus strains.
Bowel movement frequency and consistency didn't improve, but bloating did (23).
Another study found significant reductions in pain and bloating during treatment with VSL#3. Researchers believe the probiotics led to an increase in melatonin, a hormone involved in digestive function (24, 25).
Recommended Probiotics for IBS
Summary: Certain probiotics have been shown to help relieve bloating, abdominal pain and other symptoms of irritable bowel syndrome. However, taking probiotic supplements may not improve all symptoms.
Probiotics That Might Help You Lose Weight
Some studies suggest that taking probiotic supplements may be helpful for achieving weight loss and a healthier body composition.
Animal and human studies have found that certain bacterial strains may decrease the amount of fat and calories your gut absorbs, promote a healthy balance of gut bacteria and reduce weight and belly fat (27, 28, 29, 30, 31, 32).
According to a 2014 analysis of several studies, probiotics that seem to be effective for fat loss include Lactobacillus gasseri, Lactobacillus rhamnosus and the combination of Lactobacillus rhamnosus and Bifidobacterium lactis (33).
In one study, obese men who took L. gasseri for 12 weeks experienced significant reductions in body weight and body fat, including up to an 8.5% decrease in belly fat. By contrast, the placebo group had very little change in body weight or body fat (31).
In another study, obese women who took L. rhamnosus for three weeks lost twice as much weight as those who received a placebo.
What's more, they continued losing weight during the maintenance phase of the study, whereas the placebo group gained weight (32).
Taking probiotic supplements may also help limit weight gain during times of high calorie intake.
In a four-week study, lean young men ate 1,000 excess calories per day. Those who took the probiotic formulation VSL#3 gained less weight than the control group (34).
However, because results from some studies haven't been impressive, researchers feel there isn't enough evidence at this time to draw firm conclusions about the benefits of probiotics for weight loss (35).
Recommended Probiotics for Weight Loss
Summary: Results from several studies suggest that certain probiotics may promote fat loss in obese subjects. However, further research is needed.