MICRO FRIENDS

IBS symptoms have been linked to certain changes in the gut flora. For example, people with IBS have lower amounts of Lactobacillus and Bifidobacterium in their guts, and higher levels of harmful Streptococcus, E. coli and Clostridium (7Trusted Source, 9Trusted Source).

Additionally, up to 84% of IBS patients experience bacterial overgrowth in their small intestines, which can lead to many of their symptoms (7Trusted Source).

However, whether this change is a cause or result of IBS is uncertain. Also, certain medications used to treat symptoms of IBS can damage the healthy bacteria living in the gut (7Trusted Source, 10Trusted Source).

Changes in the gut flora may influence IBS symptoms by increasing inflammation, increasing sensitivity to gas in the intestine, reducing immune function and changing digestive motility (7Trusted Source, 11Trusted Source).

Probiotics have been proposed to improve symptoms by (10Trusted Source):

• Inhibiting the growth of disease-causing bacteria
• Enhancing the immune system’s barrier functions
• Helping fight inflammation
• Slowing down bowel movements
• Reducing gas production by balancing the gut flora
• Reducing the gut’s sensitivity to gas buildup

Probiotics include “good” bacteria. These are live microorganisms that can provide health benefits when consumed (1Trusted Source).

These benefits are thought to result from the ability of probiotics to restore the natural balance of gut bacteria (4Trusted Source).

An imbalance means there are too many bad bacteria and not enough good bacteria. It can happen due to illness, medication such as antibiotics, poor diet and more.

Consequences can include digestive issues, allergies, mental health problems, obesity and more (5Trusted Source).

Probiotics are usually found in fermented foods or taken as supplements. What’s more, they appear to be safe for most people.

Probiotics are widely known for their ability to prevent diarrhea or reduce its severity.

Diarrhea is a common side effect of taking antibiotics. It occurs because antibiotics can negatively affect the balance of good and bad bacteria in the gut (6Trusted Source).

Several studies suggest probiotic use is associated with a reduced risk of antibiotic-associated diarrhea (7Trusted Source, 8Trusted Source, 9Trusted Source).

In one study, researchers found that taking probiotics reduced antibiotic-associated diarrhea by 42% (10Trusted Source).

Probiotics can also help with other forms of diarrhea not associated with antibiotics.

A large review of 35 studies found certain strains of probiotics can reduce the duration of infectious diarrhea by an average of 25 hours (11Trusted Source).

Probiotics reduced the risk of travelers’ diarrhea by 8%. They also lowered the risk of diarrhea from other causes by 57% in children and 26% in adults (12Trusted Source).

Effectiveness varies, depending on the type and dose of the probiotic taken (13Trusted Source).

Strains such as Lactobacillus rhamnosus, Lactobacillus casei and the yeast Saccharomyces boulardii are most commonly associated with a reduced risk of diarrhea (9Trusted Source, 12Trusted Source).

An increasing number of studies link gut health to mood and mental health (14Trusted Source).

Both animal and human studies find that probiotic supplements can improve some mental health disorders (15Trusted Source).

A review of 15 human studies found supplementing with Bifidobacterium and Lactobacillus strains for 1–2 months can improve anxiety, depression, autism, obsessive-compulsive disorder (OCD) and memory (15Trusted Source).

One study followed 70 chemical workers for 6 weeks. Those who consumed 100 grams of probiotic yogurt per day or took a daily probiotic capsule experienced benefits for general health, depression, anxiety and stress (16Trusted Source).

Benefits were also seen in a study of 40 patients with depression.

Taking probiotic supplements for 8 weeks decreased depression levels and reduced levels of C-reactive protein (a marker of inflammation) and hormones such as insulin, compared to people who did not take a probiotic (17Trusted Source).

Certain probiotic strains may reduce the severity of eczema in children and infants.

One study found eczema symptoms improved for infants fed probiotic-supplemented milk, compared to infants fed milk without probiotics (23Trusted Source).

Another study followed children of women who took probiotics during pregnancy. Those children had an 83% lower risk of developing eczema in the first two years of life (24Trusted Source).

However, the link between probiotics and reduced eczema severity is still weak and more research needs to be done (25Trusted Source, 26Trusted Source).

Some probiotics may also reduce inflammatory responses in people with milk or dairy allergies. However, the evidence is weak and further studies are needed (27Trusted Source).

Probiotics may help with weight loss through a number of different mechanisms (40Trusted Source).

For example, some probiotics prevent the absorption of dietary fat in the intestine.

The fat is then excreted through feces rather than stored in the body (41Trusted Source, 42Trusted Source).

Probiotics may also help you feel fuller for longer, burn more calories and store less fat. This is partly caused by increasing levels of certain hormones, such as GLP-1 (43Trusted Source, 44Trusted Source).

They may also help with weight loss directly. In one study, dieting women who took Lactobacillus rhamnosus for 3 months lost 50% more weight than women who didn’t take a probiotic (45Trusted Source).

Another study of 210 people found that taking even low doses of Lactobacillus gasseri for 12 weeks resulted in an 8.5% reduction of belly fat (46Trusted Source).

However, it’s important to be aware that not all probiotics aid in weight loss.

Surprisingly, some studies found certain probiotics, such as Lactobacillus acidophilus, can even lead to weight gain (47Trusted Source).

More studies are needed to clarify the link between probiotics and weight (48Trusted Source).