Biological effects of water with reduced deuterium content have been studied in a series of studies conducted on plants, animals and humans and published in specialized journals.
In short, these effects can be grouped as follows:

Experiments conducted on plants have shown an increase in productivity, for example an increase of 56% in the case of wheat and 25% in the case of tomatoes and cucumbers.

Experiments conducted on chicken samples exposed to radiation have shown a reduction in mortality rate up to 50% and an increase in the number of eggs laid in the case of samples that consumed water with reduced deuterium content.

The mechanisms that lead to these biological effects are little known and probably have to do with changes suffered at the interference of deuterium with nuclear structures and enzyme structures, caused by the replacement of deuterium bonds with hydrogen bonds, which are more favorable for the efficient functioning of living cells.