Prebiotics are thought to be a potential means to prevent antibiotic-associated diarrhoea because of their ability to stimulate beneficial bacteria. In-vitro results showed a promising recovery of Bifidobacteria combined with an increase of Short Chain Fatty Acids (SCFA) upon Galacto-oligosaccharides (GOS) supplementation to amoxicillin-treated microbiota. As the microbiota is nowadays considered as a key factor in human health, a further understanding of the gut microbiota functioning in-vivo is essential. This understanding of the use of specific prebiotics may possibly be beneficial in the prevention or recovery of antibiotic-disturbed microbiota. As the effects of GOS supplementation on the microbiota composition and activity from healthy adults receiving amoxicillin have never been tested in-vivo, the investigators propose the current study as a proof of principle.

Objective:

To explore whether the promising effects of GOS supplementation on the composition and activity of gut microbiota from healthy adults as found by in-vitro, can also be observed in-vivo.

Study population:

10 healthy men and women volunteers, 18 - 40 yr old

Inclusion Criteria:

• Age: 18-40 *
• BMI: 18.5-25 kg/m2
• Stable weight over the last 6 months
• Western diet
• Availability of information about birth by caesarean section and breast-feeding
• Regular defecation (~1day)
• Healthy as judge by the participant himself
• Having signed the informed consent form

Exclusion Criteria:

• Smoking or drug use
• Pregnant (include planning to be or gave birth in the last 6 months) or lactating woman
• Using contraceptive pill
• Gastro-intestinal diseases (e.g. irritable bowel syndrome, inflammatory bowel disease)
• Traveling to an Asian, African or south American country < 6 months before the study
• Hypersensitivity or food allergy for products used in this study (e.g. Lactose, Penicillin)
• Having hepatic disease and renal failure
• Using medication other than paracetamol, acetylsalicylic acid (aspirin), hay fever, asthma
• Not willing to have the family doctor be informed about participation to the study.
• Antibiotic use < 3 months before the study
• More than 3 antibiotic treatments in the last 2 years.
• Probiotic or prebiotic use < 1 month before the study*