Probiotics Studied For Chronic Constipation

BB-12 is quite possibly the most studied Bifidobacterium on the planet, with over 130 human clinical trials backing it up. It's the go-to strain for people who want to move things along in the bathroom and build a stronger immune defense — all from one tiny capsule. Whether you're fighting off winter sniffles or just trying to feel more comfortable after meals, BB-12 has the science to support you.

Bifidobacterium longum BB536 is one of the most clinically researched probiotic strains in the world, with a standout reputation for promoting regular, comfortable digestion while helping your immune system stay balanced during allergy season. Think of it as a two-in-one gut ally: it gets things moving below and keeps overactive immune responses calm above. Backed by decades of research, this strain is a go-to choice for anyone dealing with stubborn constipation or the sneezing, itchy-eye misery of seasonal allergies.

One of the most extensively researched probiotic strains on the planet, Lactobacillus casei Shirota has been clinically studied for its remarkable ability to get sluggish bowels moving again and strengthen the body's everyday immune defenses. Originally cultivated in Japan almost a century ago, it works by replenishing the good bacteria in your gut — and its benefits have been felt by millions of people worldwide. Whether you're dealing with uncomfortable constipation or simply want to stay well during cold-and-flu season, this strain has some of the deepest science behind it.

Bifidobacterium lactis HN019 is a well-researched probiotic strain best known for helping things move along in your gut — literally. It's been clinically studied for its ability to support healthy bowel movement frequency and reduce the sluggishness that comes with functional constipation. Beyond digestion, HN019 is one of the few strains with solid evidence for giving your immune system a meaningful tune-up, especially as you get older.

E. coli Nissle 1917 is one of the most research-backed and uniquely powerful probiotics on the planet — the only probiotic strain officially recommended as an alternative to prescription medication for keeping ulcerative colitis in remission. Unlike the familiar Lactobacillus or Bifidobacterium strains, this gut-guardian works by crowding out harmful bacteria, calming intestinal inflammation, and reinforcing the protective lining of your gut. If you're dealing with IBD, stubborn constipation, or a sensitive digestive system, this century-old strain may be the missing piece in your gut health puzzle.