This 2022 rodent study investigated effects of glucoraphanin supplementation during pregnancy and lactation:

“We investigated whether dietary intake of sulforaphane glucosinolate (SGS [properly termed glucoraphanin]) during pregnancy and lactation influenced composition of gut microbiota in offspring:

• Dietary intake of SGS during pregnancy and lactation caused significant changes in diversity of gut microbiota in 3-week-old offspring (SGS-3W) and 10-week-old offspring (SGS-10W).
• Plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in SGS-10W after injection of lipopolysaccharide were significantly lower than those of CON-10W group.
• There were sex differences of gut microbiota composition in both SGS-3W and SGS-10W offspring.

This study has some limitations:

1. We did not investigate mechanisms of how dietary intake of SGS during pregnancy and lactation modulated gut microbial communities in offspring.
2. We found several signaling pathways in beneficial effects of SGS food pellet, and further study of the role of maternal intake of SGS food in these pathways is needed.
3. We did not investigate mechanisms of relationships between maternal intake of SGS and long-term anti-inflammatory action in adult offspring, and further detailed study including epigenetic modification is needed.

These data suggest that dietary intake of SGS during pregnancy and lactation might produce long-lasting beneficial effects in adult offspring through persistent modulation of gut microbiota. It is likely that modulation of gut microbiota by maternal nutrition may confer resilience versus vulnerability to stress-related psychiatric disorders in offspring.”

https://www.sciencedirect.com/science/article/pii/S0955286322001681 “Long-lasting beneficial effects of maternal intake of sulforaphane glucosinolate on gut microbiota in adult offspring”

This study published results of a mother’s glucoraphanin intake where offspring never ate glucoraphanin, with beneficial effects at both 3 weeks (~prepubescent human) and 10 weeks (~young human adult). Maybe future studies will continue this paradigm on to a second or third generation to see whether there are also transgenerational epigenetic effects.

This study’s methods extracted glucoraphanin from 1-day-old broccoli sprouts into a powder containing 135 mg (0.31 mmol) glucoraphanin per gram. Each 1 kg of of treatment chow included pellets containing (2.3 mmol / 0.31 mmol) x 135 mg = 1 gram of broccoli sprout powder, 0.1% of food intake.

Per Drying broccoli sprouts, dried 3-day-old broccoli sprouts contain 10% moisture, and fresh 3-day-old broccoli sprouts contain 82.6% moisture. A gram of 1-day-old broccoli sprout powder may be an approximate equivalent of (.826 / .1) = 8 grams fresh 3-day-old broccoli sprouts for a mouse / kg of daily food intake. A human equivalent dose is (.826 / .1) x .081 x 70 kg = 47 grams of fresh 3-day-old broccoli sprouts / kg of daily food intake.

That’s about how much 3-day-old, microwaved, glucoraphanin-containing broccoli and red cabbage sprouts I eat every day, starting from 7.2 grams of seeds. I sprout another 3.5 grams of yellow mustard seeds into the mixture for taste.