I can’t see how they would be detrimental. They’re basically just water with a bit of prebiotic fibre (glucomannan), and without the massive amounts of starch contained in buckwheat or oat bran.
Livestrong.com wrote: Glucomannan contains polysaccharides, which swell with the absorption of water, making it a useful laxative. Drugs.com states that konjac glucomannan has been investigated for its role as a prebiotic, which is an agent that stimulates beneficial intestinal bacteria. A study of eight volunteers who supplemented with glucomannan found a 27 percent increase in bowel movement frequency, as well as the improved ease of passage of stool. Shirataki noodles can aid in constipation, as well as help with hemorrhoids and diverticulitis.