Galacto-oligosaccharides

Studies in people

• Benefit

  Gut bacteria and IBS²

  Galacto-oligosaccharides feed gut bacteria, and small amounts may ease IBS symptoms, but scientists do not yet know for sure.

• Benefit

  Inflammation in overweight adults³

  In some studies, galacto-oligosaccharides lowered a marker of inflammation in overweight adults, but scientists say more trials are needed.

• Benefit

  Skin dryness in women⁴

  Daily galacto-oligosaccharides restored serum p-cresol levels and skin conditions in adult women.

• Benefit

  Gut health in older adults⁵

  Galacto-oligosaccharides feed good gut bacteria, but scientists do not yet know how much older people should take.

• Benefit

  Immune and metabolic health⁶

  Galacto-oligosaccharides may help immunity, calcium absorption and markers of metabolic syndrome in people.

• Open question

  Anxiety and brain chemistry⁷

  In young women, galacto-oligosaccharides did not clearly lower anxiety, though brain chemistry and gut bacteria changed.

• Open question

  Gut bacteria in diabetes⁸

  In people with type 2 diabetes, galacto-oligosaccharides restored Bifidobacteriaceae, but LBP and glucose tolerance did not improve in this short trial.

• No harm found

  Blood sugar control in diabetes⁹

  In men with type 2 diabetes, galacto-oligosaccharides did not improve blood sugar control over 12 weeks.

• Benefit

  Gut bacteria in children¹⁰

  In children, galacto-oligosaccharides with Lactobacillus GG raised helpful bifidobacteria in the gut more than the bacteria alone.

• Benefit

  Constipation in older women¹¹

  In older women with constipation, galacto-oligosaccharides helped them go to the toilet more often.

• Benefit

  Iron absorption in infants¹³

  In Kenyan infants, galacto-oligosaccharides added to iron-fortified maize porridge increased how much iron their bodies absorbed.

• Open question

  Blood sugar control¹⁴

  In people with prediabetes, taking galacto-oligosaccharides for 12 weeks raised gut Bifidobacterium but did not change insulin sensitivity.

Study type not stated

• Benefit

  Prebiotic evidence gaps¹⁵

  Galacto-oligosaccharides are prebiotics that feed gut bacteria, but most studies were done in lab dishes, not people.

• Concern

  Gut bacteria and digestion¹⁶

  Galacto-oligosaccharides feed good gut bacteria, but large amounts can cause gas and loose stools.

• Benefit

  Gut health and germs¹⁷

  Galacto-oligosaccharides feed good gut bacteria and may block bad ones from sticking.

• Benefit

  Infant gut bacteria¹⁸

  Galacto-oligosaccharides help good bacteria like bifidobacteria grow in babies' guts and support the gut barrier.

How it’s made and used

• Small intestine digestion¹²

  In healthy adults, most galacto-oligosaccharides passed through the small intestine undigested, though some smaller ones broke down.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.