Considering that WG has a modest fiber content (3%–4%) but is a rich source of tryptophan (up to 300 mg per 100 g WG) [[28], [29], [30]], it is plausible that the potential of WG to increase Lactobacillus in HF-fed mice resulted in indole metabolites that activated the IL-22–STAT3 pathway, resulting in elevated Reg3 AMPs. Here, IL22 is linked to hydrops fetalis.