To date, 14 studies have investigated GSH, GSSG, GSH/GSSG and/or tGSH levels in the plasma of healthy adults (Andriollo-Sanchez et al., 2005, Chillemi et al., 2005, Giustarini et al., 2006, Hernanz et al., 2000, Houze et al., 2001, Jones et al., 2002, Kretzschmar et al., 1991, Maciejczyk et al., 2019, Michelet et al., 1995, Nuttall et al., 1998, Paolisso et al., 1998, Rea et al., 2004, Samiec et al., 1998, Yang et al., 1995), with the majority using HPLC (N = 10, 71%) (Chillemi et al., 2005, Giustarini et al., 2006, Hernanz et al., 2000, Houze et al., 2001, Jones et al., 2002, Michelet et al., 1995, Paolisso et al., 1998, Rea et al., 2004, Samiec et al., 1998, Yang et al., 1995), and the remaining using colorimetry (N = 2, 14%) (Kretzschmar et al., 1991, Maciejczyk et al., 2019), enzyme-rate essay (Nuttall et al., 1998) (N = 1, 7%), and spectrophotometry (N = 1, 7%) (Andriollo-Sanchez et al., 2005) (Table 3)

Smith MC, Madec S, Coton E, Hymery N (2016) Natural co-occurrence of mycotoxins in foods and feeds and their in vitro combined toxicological effects
thus, it has often been recommended that men opt for plant-rich diets such as vegetarianism, DASH, or Mediterranean regimens either alone or coupled with antioxidant supplementation [230,231]
Published research (Stoeva MK et al., Gut Microbes, 2021) on Clostridium butyricum confirms it is a direct butyrate-producing organism in the gut