Final answer:
The change that would NOT be expected to lead to a reduction of ISC proliferation in the gut epithelium is the addition of lactate to the microbiota environment near the ISCs, as lactate is a beneficial metabolite for these cells.
Step-by-step explanation:
To answer the question regarding which change would NOT be expected to lead to a reduction of intestinal stem cell (ISC) proliferation in the gut epithelium, we should look at the different options provided:
- Use of antibiotics to treat colitis, which is associated with dysbiosis.
- A microbiota Lactobacillus plantarum strain that lacks the ability to produce lactate.
- Reduced activity of a lactate-sensitive G-protein-coupled receptor.
- Addition of lactate to the microbiota environment near the ISCs.
Option 1 involves the use of antibiotics, which can disrupt the balance of the gut microbiome, potentially leading to reduced ISC proliferation due to an unfavorable shift in the microbial community. Option 2 suggests a microbiome deficient in producing lactate, which could lead to a similar reduction in ISC proliferation, as lactate is known to be an important source for these cells. Option 3, reduced activity of a lactate-sensitive receptor, would likely cause a reduction in ISC proliferation because the normal lactate signaling would be impaired. However, option 4, the addition of lactate to the microbiota environment, would presumably support ISC proliferation since lactate is a beneficial metabolite that helps in the function and maintenance of these cells. Therefore, Option 4 would NOT be expected to lead to a reduction in ISC proliferation.