What that means is if there isn't enough good bacteria, you're not likely to get the most out of the food you eat.

Although these 'friendly bacteria' are unlikely to cause serious side effects, it's best to check before making any changes to your diet when you're pregnant.

Mothers who drink milk containing 'friendly bacteria' (probiotics) while pregnant and breastfeeding may reduce their child's risk of developing eczema, reports a new study.