The goal of this R & D is to explore the effects of vitamin B6 and poly-gamma-glutamic acid (PGA). PGA is a natural bio-new material isolated from Cheonggukjang, traditional fermented food in Korea. We intend to evaluate the effects of this supplementation in relevant physiological, metabolic, and inflammatory indicators and through questionnaire-based sleep quality assessments in a randomized, double-blind, placebo-controlled, crossover trial.

Treatment

*Types of intervention (3 types):All supplements were provided in a powder presentation. 
- Intervention A: poly-γ-glutamic acid (γ-PGA) (600 mg) OR placebo (corn starch 600mg)
- Intervention B: vitamin B6 (pyridoxine) (100 mg) OR placebo (corn starch 100mg)
- Intervention C:  poly-γ-glutamic acid (γ-PGA) (600 mg) + vitamin B6 (pyridoxine) (100 mg) OR placebo (corn starch 700mg)

Duration: Stage 1 (4 weeks) → Wash out (4 weeks)  → Phase 2 (4 weeks)

* Total number of research participation: 4 times (baseline and follow-up for each of them phase 1 and 2)

* The number of participants who completed the 4 required meetings: 47
  - Group A: 16
  - Group B: 14
  - Group C: 17

Arm Label

Target Number of Participant

Arm Type

Arm Description

* Intervention types 
  -Intervention group A: polygamma glutamic acid (γ-PGA, 600 mg) or placebo (corn starch, 600 mg)

* Arbitration period: Stage 1 (4 weeks) → Wash-out(4 weeks) → Stage 2 (4 weeks)

* Total number of research participation: 4 times (baseline stage 1 and stage 2,  and follow-up stage 1 and stage 2)

* The number of subjects who completed the 4 study participation meetings: 16

Arm Label

Target Number of Participant

Arm Type

Arm Description

* Intervention types 
  -Intervention group B: Vitamin B6 (pyridoxine, 100 mg) or placebo (corn starch, 100 mg)

* Arbitration period: Stage 1 (4 weeks) → Wash-out(4 weeks) → Stage 2 (4 weeks)

* Total number of research participation: 4 times (baseline stage 1 and stage 2,  and follow-up stage 1 and stage 2)

* The number of subjects who completed the 4 study participation meetings: 14

Arm Label

Target Number of Participant

Arm Type

Arm Description

* Intervention types 
  -Intervention group C: polygamma glutamic acid (γ-PGA, 600 mg) plus Vitamin B6 (pyridoxine, 100 mg) or placebo (corn starch, 700 mg)

* Arbitration period: Stage 1 (4 weeks) → Wash-out(4 weeks) → Stage 2 (4 weeks)

* Total number of research participation: 4 times (baseline stage 1 and stage 2,  and follow-up stage 1 and stage 2)

* The number of subjects who completed the 4 study participation meetings: 17

Gender

Age

Description

Adult participants aged 20-65 years with no history of chronic disease including CVD, diabetes mellitus, cancer, hepatic disease, or kidney disease. 
All enrolled participants signed an informed consent form, which was approved by the Human Subjects Review Committee at the Kookmin University (KMU-201808-HR-184).

- Participants with regular use of drugs to treat the previously mentioned diseases 
- Pregnant
- Those currently taking dietary supplements
- Those diagnosed with allergic symptoms or with anemia diagnosis in the last three months.

Sleep duration

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Sleep onset latency

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Pittsburgh Sleep Quality Index (PSQI)

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Epworth Sleepiness Scale (ESS)

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Insomnia Severity Index (ISI)

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Caffeine intake

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Serotonin

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Change in the gut microbiome

After supplement intervention [ 2nd meeting (4th week) and 4th meeting (12th week) ]

Carolina Garcia Garcia. Effects of poly-γ-glutamic acid and pyridoxine on sleep status in a clinical study
임상 연구에서 폴리감마글루탐산와 피리독신이 수면 상태에 미치는 영향. Kookmin University Sungkok Library. Non SCI. 2020-02-19 ,
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														http://www.riss.kr/search/detail/DetailView.do?control_no=ad2d5ef05259f8f8ffe0bdc3ef48d419&p_mat_type=be54d9b8bc7cdb09&p_submat_type=f1a8c7a1de0e08b8&fulltext_kind=a8cb3aaead67ab5b&t_gubun=&convertFla
														

Data regarding the effects of poly-γ-glutamic acid (γ-PGA) on sleep are limited. This study aimed to test whether γ-PGA and vitamin B6 (VitB6) supplements improve sleep. A factorial randomised, double-blinded, placebo-controlled crossover study included 47 adults absent of chronic diseases or under medical treatment. Stratified randomised allocation considered age and gender for the three intervention groups: A-supplementation with γ-PGA (600mg) alone (n=16), B-supplementation with VitB6 (100 mg) alone (n=14), and dual C-supplementation of these two compounds (n=17). Participants underwent a one-month intervention period, followed by a one-month washout period, and then a second one-month intervention period. Before and after intervention periods, information about nighttime sleep status was collected at Kookmin University (KMU). Differences in sleep status before and after supplementation were compared between the placebo and intervention groups using non-parametric tests finding significant statistical differences in the dual C-supplementation intervention: an increase in sleep duration (0.27±0.98 hour, p <0.05) (A-Supplementation=-0.03±0.71, p=0.23; B-supplementation=0.67±0.80, p=0.60) and a reduction in Pittsburgh Sleep Quality Index global score (-0.52±1.58, p <0.05). No side effects were reported. On the basis of these findings, C-supplementation may be effective as functional food components to improve nighttime sleep. The protocol was approved by KMU IRB (KMU-201808-HR-184). Funding by the Korean government (2017R1A2A2A05001380).