PGX is a proprietary fibre supplement manufactured by InovoBiologic, produced from konjac (glucomannan), sodium alginate and xanthan gum. InovoBiologic also produced the psyllium (PSY) supplement used in the study.
Fibre shows beneficial effects
“Both the PGX and PSY groups demonstrated significant reductions at three months in fasting concentrations of total cholesterol by 8.2% and 7% respectively, LDL cholesterol by 13.9% and 8.1% respectively, insulin by 9% and 9.4% respectively and HOMA2-IR [assessment of insulin resistance] score by 11.9%, compared to control group,” wrote the authors.
“Only the PGX intervention improved fasting glucose and HDL cholesterol during the study,” they added in the study published in the journal Nutrients.
Researchers in Perth, Australia, provided subjects with PGX, PSY or rice flour as a control in 5g doses, to be taken with water three times a day before meals, according to a randomised double blind protocol.
Subjects consisted of 159 adults aged 19 to 68 with BMIs between 25-47 kg/m2, with 93 subjects completing all 12 months of the study.
One of the study’s authors has a financial interest in PGX, while another receives consulting fees from InovoBiologic. InovoBiologic also provided the supplements for the study.
The researchers found no significant differences between PSY and PGX for most measures, except for lower total glucose at three months for PSY.
Compared to the control group, HDL cholesterol was significantly higher in the PGX group at 12 months but not in the PSY group. LDL cholesterol was significantly lower in the PGX group at three and six months compared to control whereas LDL cholesterol was only significantly lower in the PSY group at three months compared to control. Glucose was significantly lower in the PGX group at three months but not in the PSY group.
Larger trial into fibre supplements
The authors said this study forms part of a larger trial into PGX.
“One of the strengths of this study was the duration, with a 12 months intervention period. Comparable studies have only been conducted for 14 weeks. This allowed us to investigate the long term effects of the fibre supplements, especially weight maintenance,” they wrote.
The authors said PGX swells in the stomach, increasing feelings of fullness, due to its high viscosity: “Psyllium has also been shown to increase fullness but has a far lower viscosity than PGX. This characteristic may have caused participants to decrease their food intake, which then lead to significant weight loss.
“The changes to blood lipids and insulin observed are likely due to the changes in dietary intake and weight loss observed as well as the possible effect of PGX slowing gastric emptying and absorption of nutrients in the small intestine."
Published online ahead of print, doi: 10.3390/nu9020091
“Effect on Insulin, Glucose and Lipids in Overweight/Obese Australian Adults of 12 Months Consumption of Two Different Fibre Supplements in a Randomised Trial”
Authors: Pal, S.; Ho, S.; Gahler, R.J.; Wood, S.