Study of the Effects of Soy Exposure in Early Life on Bone Development and Gut Microbiota

In this project, the investigators aim to investigate the effects of soy consumption at early life on the development of gut microbiota and bone growth. The hypothesis to be tested is that early-life exposure to soy optimize bone growth via the alteration of gut microbiota composition. Clinical samples from mother-child pairs recruited into the SMART Gen Hong Kong cohort will be used to examine the association between maternal soy intake with infant gut microbiota and child's bone development. Primary outcome: Bone mineral density; dynamic bone formation parameters; messenger ribonucleic acid (mRNA) expression of bone markers. Secondary outcome: Gut microbiome profile; metabolomic profile in serum, urine or feces; correlation between soy-induced gut microbiota or metabolites and bone growth. The investigators expect that early life exposure to soy will improve bone growth via gut microbiota and provide scientific evidences for the use of soy preparation in early life as a preventive measure for optimizing bone health.

Inclusion Criteria for healthy pregnant women: 1. Chinese mothers aged 18 - 45 years who were in the first trimester of pregnancy 2. Singleton pregnancy 3. Participate voluntarily and capable of giving informed consent Inclusion Criteria for babies: The baby of enrolled pregnant women and parents signed written informed consent prior to the initiation of this study. Exclusion Criteria: 1. Significant medical conditions especially those required long term medications, such as oral steroid, antihypertensive drugs, diabetic medications and lipid-lowering agents, during or before pregnancy 2. History of chronic inflammatory or neoplastic diseases involving the gastrointestinal tract (e.g. inflammatory bowel disease, coeliac disease, colorectal cancer) 3. Significant pregnancy complications, such as intrauterine foetal demise/stillbirth, extreme prematurity, or pre-labour rupture of membranes before 24 weeks 4. Mother with mental incapacity such that they are not able to give informed consent 5. Foetal chromosomal or clinically significant structural abnormalities 6. The current pregnancy is a conception through either sperm or ovum donation