Combined with our previous finding that d-mannose can rescue the defects of Tph2 histone acetylation in CRS-exposure mice by directly entering the brain, we propose that d-mannose can also activate ACSS2–PPARγ–TPH2 axis via elevating brain SCFAs and reversing the dysbiosis of the gut microbiota in CRS mice. This evidence concerns the gene ACSS2 and congenital rubella syndrome.