Agglomerated glucomannan, oligofructose and chromium mixture as the functional ingredient in a calorie

Participants visited the University of Roehampton on three separate occasions: visit 1 (screening), visit 2 (baseline), and visit 3 (end of the trial) in total over a period of 4-weeks. During the 4-week study period, participants were instructed to replace breakfast and lunch with a shake (206 kcal/shake) each delivering 3g of the active ingredient (Mix: agglomerated glucomannan, oligofructose and chromium picolinate), and one snack bar each delivering 1.5g of the active ingredient (112 kcal/bar) in between breakfast and lunch, and lunch and dinner following by a selection of healthy dinner according to standard nutritional guidance not exceeding 1500 kcal/day. All subjects were instructed to prepare shakes by using a shaker or blender by mixing all ingredients with 200 ml of water. Participants were also instructed to consume all shakes and bars with an extra 200 ml glass of water throughout the study period.

The body mass was measured to the nearest 0.1 kg using a digital balance scale (Seca 707, Seca Corporation, Hamburg, Germany)

Body mass index was determined as weight divided by height squared (kg/m^2)

Blood pressure was measured using a digital blood pressure monitor (Nissei, model DS-1902, Japan Precision Instruments, Inc., Gunma, Japan).

Body fat percentage was assessed after a 12-hour water-only fast by bioelectrical impedance analysis (BIA) method, using a Tanita BC-418 MA Segmental Body Composition Analyser, which incorporates eight tactile electrodes (Tanita Corporation, Tokyo, Japan).

Waist was assessed using anthropometric tape (Seca 201, Hamburg, Germany) over light clothing to the nearest 0.1 centimetre while the subjects were in the standing position at the end of gentle expiration. The waist circumference was measured at the mid-point between the lowest rib margin and anterior superior iliac crest and hip circumference was measured at the maximum protuberance of the buttocks, and the waist-to-hip ratio was calculated by dividing waist circumference by hip circumference.

Sequencing was performed on an Illumina MiSeq desktop sequencer using the MiSeq Reagent Kit V2 (Illumina, San Diego). The significance in the abundance of the relevant taxa were validated by Wilcoxon signed-rank tests (16s rRNA sequencing using Illumina MiSeq Platform and QIIME data analysis software).