Galacto-what?

Galactooligosaccharides are a type of carbohydrate and fibre known as prebiotics. Humans don’t digest fibre but the healthy bacteria in our gastrointestinal (GI) tracts do. In essence, prebiotics are food for our healthy gut bacteria.

Researchers randomly selected 419 college students to take a placebo pill (no prebiotics), or 2.5 or 5 grams per day of galactooligosaccharides for eight weeks, around the time of final examinations. The students completed daily assessments of stress levels (presumably, examinations supplied the stress), noting the frequency and severity of cold or flu symptoms, and they keeping a weekly journal of GI symptoms, such as diarrhoea, constipation, and heartburn (reflux).

At completion of the study, the researchers noted that:

• Students who reported higher stress levels experienced more diarrhoea, indigestion, and reflux with abdominal pain; more days of cold and flu symptoms; and more severe cold and flu symptoms overall.
• GI distress scores for diarrhoea, constipation, and abdominal pain were lower after galactooligosaccharide supplementation.
• The intensity of cold and flu symptoms was lower in students taking 2.5 grams of prebiotics at all stress levels, but only the 5-gram daily dose of galactooligosaccharides lowered symptom intensity in students with lower stress levels.
• 5 grams of galactooligosaccharides reduced the number of days with cold or flu symptoms in normal-weight students, but not in overweight or obese students.

Busting stress, feeling better

This study indicates that acute mental stress can increase GI and cold or flu symptoms. The results also suggest that supplementation with galactooligosaccharides may reduce these symptoms and the number of days with cold or flu. To protect your tummy, try the following:

• Consider prebiotics. Ask your doctor if a prebiotic dietary supplement is right for you. If you start taking them, go slow, to let you body adjust to the increased intake of undigestible carbohydrates, and drink plenty of water.
• Stroll away from stress. Regular exercise may decrease stress levels and increase immune function. Take a walk with friends or hit the gym in between study sessions or tough work assignments.
• Favour real food. Highly processed and junk foods, such as biscuits, crisps, candy, cakes, cookies, and other baked goods can upset digestion and increase bloating and other symptoms. Stick to whole healthy foods such as vegetables, fruit and dried fruit, nuts, and seeds for study session snacking.

(Am J Clin Nutr 2011; 93:1305–11)