摘要：Prebiotics affect mineral absorption, in part by increasing solubility due to short chain
fatty acid generation. Prebiotics stimulate the growth of probiotics in the gut and probiotics may
affect mineral absorption by similar mechanisms. The objectives of this study were to measure
(1) the effect of Lactobacillus rhamnosus strain HN001 (HN001) on mineral absorption in growing male rats and (2) whether HN001 can reduce bone loss and affect bone properties in female
ovariectomised (OVX) rats. Study 1: Twenty-two 3-week-old Sprague-Dawley rats were weaned
onto a milk powder-based diet supplying 20% protein and 0.5% calcium. After a week, the rats
were randomised into two groups: one continuing on the base diet and the other receiving $10^9$ cfu
HN001 per day in the diet. After 3 weeks, the animals were housed in metabolic cages for 8 days.
Food intake was measured, and urine and faeces were collected for 3 days. Calcium and magnesium
balances were calculated. Study 2: Forty 5.5-month-old female Sprague-Dawley rats were
ovariectomised or sham-operated and randomised into three groups. The sham ($n = 10$) and OVX
control groups ($n = 15$) remained on a caseinate-based control diet, while the experimental group
($n = 15$) received $10^9$ cfu HN001 per day in the diet. After 12 weeks, bone density was measured
by dual energy X-ray absorptiometry and bone and blood samples were collected. HN001 improved
calcium and magnesium retention in the growing male rats, but due to differences in food intake,
data was inconclusive. However, HN001-fed OVX rats had a reduced rate of bone loss and a higher
final bone density in the spine and femur at week 12 compared to the OVX control group. HN001
may improve mineral bioavailability and have a positive effect on bone mineral density and mineral
content. The underlying mechanisms need to be researched.
