Beneficial glycaemic effects of barley bread compared to wheat bread in type 2 diabetes

doi:10.21203/rs.3.rs-2607823/v1

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Beneficial glycaemic effects of barley bread compared to wheat bread in type 2 diabetes

https://doi.org/10.21203/rs.3.rs-2607823/v1

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published 08 Nov, 2023

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Background:

Cereals foods with a high content of dietary fibres or amylose have potential to lower postprandial glucose levels. Optimisation of cereal foods may delay development of or improve management of type 2 diabetes (T2D).

Methods:

We investigated the impact on postprandial glucose metabolism of bread made of hulless barley flour (50% or 75%) and wheat flour (50% or 25%) or an RNAi-based amylose-only barley flour (AmOn) (50%) and wheat flour (50%) in subjects with T2D.

Design:

Twenty adults with T2D were randomly allocated to one of four bread each corresponding to 50 g carbohydrate at four separate visits. We measured fasting and 4h postprandial responses of glucose, insulin, glucagon, triacylglycerol, free fatty acids, glucagon-like peptide-1 and gastric inhibitory polypeptide. Mixed model ANOVA was used to examine the differences.

Results:

Bread made from 50% AmOn lowered the postprandial glucose by 34%, 27%, 23% (P < 0.05) compared with 100% wheat, 50% or 75% hulless barley, respectively. Bread made from 75% hulless barley reduced the postprandial glucose by 11% (P < 0.05) compared to 100% wheat bread.

Postprandial insulin responses were reduced for 50% AmOn by 24% and 35% (P < 0.05) compared with 100% wheat and 50% hulless barley, respectively. Postprandial insulin was reduced by 22% (P < 0.05) for 75% compared to 50% hulless barley bread.

Conclusions:

Bread made by replacing wheat flour with either 75% hulless barley or 50% AmOn flour lowered postprandial glucose responses compared to 100% wheat bread indicating a beneficial impact in management of T2D.

This trial was registered at clinicaltrials.gov as NCT04646746.

Health sciences/Endocrinology/Endocrine system and metabolic diseases/Diabetes/Type 2 diabetes

Health sciences/Diseases/Endocrine system and metabolic diseases/Diabetes

The increasing prevalence of diabetes is primarily due to obesity, lack of physical activity and unhealthy diet. Therefore, it is important to identify and generate foods and diets that counteracts the development of type 2 diabetes (T2D). Diets low in glycaemic index (GI) and glycaemic load have the potential to prevent T2D (1–5) or to improve management of T2D and cardiovascular diseases (6).

Cereals e.g., rice, wheat, rye, oat and barley are staple foods worldwide. The content of dietary fibres (7–9) and the composition of starch both affect glucose metabolism in diabetic (10) and non-diabetic subjects (11, 12). Starch consists of amylose (being mostly linear 1,4-α-glucan) and amylopectin (a branched polymer that mainly consists of 1,4-α linkages with branches of 1,6-α-glucan types). The amount of amylose is between 15–30% in most cereal and tuberous crops. In barley, three different starch branching enzymes (SBEs) are involved in the formation of amylopectin. By suppressing these three SBE genes, amylopectin formation is virtually blocked and only amylose and amylose-like glucans are formed (13). By genetic modification, this formation was achieved in barley hereby increasing the amount of amylose to more than 99% of the starch (14). In vitro this type of gene-modified high amylose barley (AmOn) suppressed GI to 10–15 (15).

High-amylose starches are more slowly degraded and contain a relatively higher amount of resistant starch (RS) compared to normal-amylose starches (13, 14). Slowly digestible starch and RS decreases GI (16, 17).

Barley flour has lower GI in humans than wheat flour (18, 19) and possesses positive effects on the gut microbiome, endogenous gut hormones responses and appetite regulation (20). How the food is processed may affect the postprandial glucose metabolism since processing can alter the physicochemical characteristics of starch and dietary fibres (21). Most cultivated barley varieties are hulled. In western countries barley contributes very little as staple food but is used for livestock feed and to produce beer malt. Interestingly, barley has a number of favourable properties that we can take advantages of. Farmers use significantly less nitrogen for barley fields than for wheat fields and barley tolerates climate changes better than wheat (22). For bread making hulless barley is preferred over hulled barley due to better baking qualities (23), but it is not yet clarified how hulless barley affects GI in T2D.

We carried out a single-blinded, randomised, acute study in subjects with T2D to clarify effects on the glycaemic responses to different breads made of wheat, hulless barley and AmOn. We hypothesised that bread made from hulless barley or AmOn improves glucose metabolism compared to wheat bread in subjects with T2D.

Study design

The study was performed as an acute randomised, single-blinded, intervention with 4 test meals consisting of breads made with a mix of hulless barley flour (50% or 75%) or AmOn flour (50%) with wheat flour (50% or 25%) and compared to 100% wheat flour bread. The study participants were randomised to the order of visits using RedCap®.

The primary outcome, postprandial glucose metabolism, was evaluated by calculating the incremental area under the glucose response curve. The secondary outcomes were postprandial insulin, glucagon, triglyceride (TG), free fatty acids (FFA), glucagon like peptide 1 (GLP-1), and gastric inhibitory polypeptide (GIP) responses.

Participants were fasting at all meal test days. Smoking was not permitted at the fasting visits. Alcohol consumption was not permitted for two days before the fasting visits and strenuous exercise was not permitted the day before the fasting visits. Anti-hypertensive and anti-diabetic drugs were paused 24 hours before every study day. The four intervention days were separated by at least six days.

Study participants

Twenty Caucasian participants with T2D were recruited through local newspapers and electronic advertisement to participate in the study. The study was conducted at the Department of Endocrinology and Internal Medicine, Aarhus University Hospital, between March 2021 and October 2021. After receiving written and oral information, all participants gave their written informed consent before participating in the study. Participants were screened on the basis of their medical history and a physical examination. The inclusion criteria were as follows: All subjects were classified as having diabetes based on International Diabetes Federation criteria (24).

The exclusion criteria were: type 1 diabetes, insulin treated T2D, use of weekly administrated GLP-1 antagonist, use of acarbose, significant cardiovascular, kidney, liver or endocrine comorbidity, significant psychiatric history, treatment with steroids, alcohol or drug abuse, pregnancy or breastfeeding, or legal incompetence.

Treatment with drugs for hypertension or high cholesterol was allowed if the treatment dose was stable throughout the study period. Participants were encouraged to maintain their present psychical activity level and their smoking and alcohol habits during the study period.

The study protocol was carried out in accordance with the Helsinki Declaration of 1975 as revised in 1983 and was approved by the Central Denmark Region Committees on Health Research Ethics (1-10-72-299-20). The study was registered at clinicaltrials.gov as NCT04646746.

Production of dietary supplements and dietary assessment

All participants were provided with a standard meal for dinner the night before each study day. The meals were commercially produced ‘chili con carne’ (Salling Group A/S, Denmark). The women’s meal contained 536 kJ and the men’s meal contained 638 kJ.

Bread with 100% wheat flour (standard commercial Manitoba wheat flour, HavneMøllen, Vejle, Denmark) and bread mixed of wheat and hulless barley flour were produced by ‘P.A. Andersen bakery’ (Vejle, Denmark), whereas bread made from a mixture of wheat and AmOn flour was produced at ‘Plantcarb ApS’ (Slagelse, Denmark), since genetically modified flour is not allowed in Danish commercial bakeries. All four bread types were packed in individual bags containing either 114 g (100% wheat), 119 g (50% hulless barley), 122 g (75% hulless barley) or 128 g (50% AmOn) of bread corresponding to 50 g of carbohydrate based on calculations from ‘Vitakost ApS’ (Kolding, Denmark). The grains were grown in field plots over the summer of the year 2021 at Aarhus University (Flakkebjerg, Denmark). Whole grains of AmOn were ground into flour by a Komo Fidibus 21 benchtop mill (KOMO GMBH & CO. KG, Hopfgarten, Germany). The breeding and characterisation of starch from the AmOn barley variety has previously been described (14). In brief, the AmOn was based on a hulled barley variant (H. vulgare var. golden promise) and was bred to contain more than 99% amylose of the starch fraction by introducing a chimeric RNAi hairpin DNA construct that simultaneously reduced the expression levels of the genes SBEIIa, SBEIIb and SBEI by more than 90%. The hulless barley (H. vulgare var. PS3) used in this study was developed by the breeder Agrologica (Mariager, Denmark).

Bread component analysis

The moisture content was determined by the weight loss after drying in a 120°C oven for 24 hours. The total starch and fibre contents were determined using the Megazyme total starch assay kit (K-TSTA, Megazyme, Co. Wicklow, Ireland) and Megazyme total fibre assay kit (K-TDFR-200A, Megazyme, Co. Wicklow, Ireland), respectively, following the manufacturer’s instructions.

In vitro starch digestibility was measured according to the Englyst method (25). Rapidly digestible starch (RDS) was defined as starch digested within 20 min of digestion, slowly digestible starch (SDS) was defined as starch digested between 20 and 120 min, and RS was the part not digested after 120 min digestion.

Visits

After signing the informed consent form, screening blood samples were analysed for alanine aminotransferase, HbA1c, fasting glucose, TG, thyroid-stimulating hormone, sodium, potassium, creatinine, and haemoglobin.

After a standardised evening meal and an overnight fast, the study participants arrived at the clinic between 07.00-07.30 AM at all four study days. A catheter was placed in a cubital vein for blood sampling. Baseline blood samples were drawn (at timepoints − 10 and 0 min), and then the test bread was consumed within the next 10 min together with 250 ml of tap water.

During the following four hours blood samples were drawn at specified time points: glucose, insulin, and glucagon at -10, 0, 10, 20, 30, 45, 60, 90, 120, 150, 180, 210, and 240 min; TG, FFA, GLP-1 and GIP at -10, 0, 30, 60, 120, 180, and 240 min. All blood samples were immediately centrifuged at 3000 g for 10 min at 4°C; thereafter, the plasma samples were frozen at -20°C and the next day stored at -80°C.

Blood analyses:

Plasma glucose was measured by a glucose oxidase method with a GOD-PAP glucose kit (no. 11491253216; Roche Diagnostics GmbH, Germany). Serum insulin and glucagon were measured with ELISA (insulin no. 10-1113-01 and glucagon no. 10-1271-01; Mercodia AB, Sweden). Plasma TG and FFA concentrations were measured with enzymatic colorimetric assays by using commercial kits (no. 04657594190, Roche Diagnostics GmbH, Germany, for TG and code 270–7700, Wako Chemicals GmbH, Germany, for FFA). Measurements of both parameters were made on a Cobas c111 analyser (Roche Diagnostics GmbH, Germany). GLP-1 and GIP were measured with NL-ELISA techniques (GLP-1 no. 10-1278-01 and GIP no. 10-1258-01; Mercodia AB, Sweden).

Statistical analysis:

The power calculation was based on previous results from our group and made to detect a difference in our primary outcome (i.e., postprandial glucose response, given as incremental area under the curve (iAUC)) of 20% between diets (11). The number of participants needed to complete the study and achieve a statistical power of 80% was calculated to be 20 (a < 0.05, b = 0.80). A mixed model ANOVA was used to examine the effect of each bread type compared with the wheat bread (control). P < 0.05 was considered statistically significant. Results are given as mean ± 95% confidence interval (CI), unless otherwise stated. All statistical calculations were performed with STATA version 17 (StataCorp LP, Texas, USA) and GraphPad Prism 6 (GraphPad Software, Boston, USA) was used to generate the graphical elements.

Baseline clinical characteristics

20 participants were randomised and 18 completed all meal tests. One participant was excluded since no intravenous access could be obtained and one dropped out due to personal reasons. Table 1 presents baseline clinical characteristics of the 18 completing participants.

72% of the participants were female; average age was 61 years (± SEM: 2.7); average HbA1c was 50 mmol/mol (± SEM: 1.1); and average BMI was 31 kg/m² (± SEM: 1.1).

Bread fibre and starch content

Table 2 presents bread analyses for total fibre, total starch, RDS, SDS and RS content in the four bread types. Total fibre content for 50% AmOn were increased by 14%, 9%, and 5% compared with 100% wheat, 50% or 75% hulless barley bread (P < 0.05), respectively. Total fibre content for 50% and 75% hulless barley compared with 100% wheat was increased by 5% and 9%, respectively (P < 0.05). Total starch content for 50% AmOn was decreased by 15%, 10%, and 7% (P < 0.05) compared with 100% wheat, 50% or 75% hulless barley, respectively. The total starch content for 100% wheat was increased by 5% and 8% compared with 50% and 75% hulless barley, respectively (P < 0.05). The RS content analysed by in vitro digestion protocol increased by 22%, 13%, and 10%, respectively, for 50% AmOn compared with 100% wheat, 50% or 75% hulless barley (P < 0.05). RS content was increased by 9% and 12% after 50% and 75% hulless barley, respectively, compared with 100% wheat (P < 0.05). The total amount of carbohydrate was similar in the four bread types with 77%, 78%, 77% and 76% of dry weight for wheat, 50% hulless, 75% hulless and 50% AmOn bread, respectively (P < 0.05).

Plasma glucose, insulin and glucagon responses

Plasma concentrations of glucose, insulin and glucagon are presented as mean changes (± SEM) from baseline in percentage together with the postprandial response in absolute terms given as incremental area under curve (iAUC) are presented in Figure 1.

Postprandial glucose responses (iAUCs) for 50% AmOn were reduced by 34% (248 mmol/L*240 min (95% CI: 175, 321; P < 0.001)), 27% (194 mmol/L*240 min (95% CI: 121, 267; P < 0.001)) and 23% (167 mmol/L*240 min (95% CI: 93, 240; P < 0.001) compared with 100% wheat, 50% or 75% hulless barley flour bread, respectively.

Postprandial glucose response was reduced by 11% (81 mmol/L*240 min (95% CI: 8, 155; P = 0.030)) for bread made with 75% hulless barley compared with that of 100% wheat flour bread.

Glucose peaks compared to fasting glucose for bread made with 50% AmOn were 1.5 mmol/L (95% CI: 0.9, 2.0; P < 0.001), 1.4 mmol/L (95% CI; 0.9, 2.0; P < 0.001) and 1.0 mmol/L (95% CI; 0.4, 1.5; P = 0.001) lower than breads made with 100% wheat, 50% or 75% hulless barley, respectively.

Postprandial insulin responses (iAUCs) were reduced by 24% (7.7 nmol/L * 240 min (95% CI; 0.5, 14.9; P = 0.035)) and 35% (13.3 nmol/L * 240 min (95% CI: 6.2, 20.5; P < 0.001)) for 50% AmOn compared with 100% wheat and 50% hulless barley, respectively. Postprandial insulin did not differ between wheat and 50% hulless barley (P = 0.121) or between wheat and 75% hulless barley (P = 0.422). However, insulin was reduced by 22% (8.5 nmol/L * 240 min (95% CI; 1.3, 15.7; P = 0.021)) for 75% hulless barley compared with 50% hulless barley.

Postprandial glucagon responses (iAUCs) were reduced for 50% AmOn and 75% hulless barley by 215 pmol/L * 240 min (95% CI: 75, 355; P = 0.003) and 156 pmol/L *240 min (95% CI: 16, 297; P = 0.030), respectively compared to 100% wheat.

GIP and GLP-1 responses

In Figure 2 we present concentrations of GIP and GLP-1 as mean changes (± SEM) from baseline in percentage, together with the postprandial iAUC responses.

After intake of test meals based on AmOn flour iAUCs for GIP were reduced by 4.6 nmol/L * 240 min (95% CI: 3.0, 6.2; P < 0.001), 3.2 nmol/L * 240 min (95% CI: 1.6, 4.9; P < 0.001) and 1.8 nmol/L * 240 min (95% CI: 0.2, 3.4; P = 0.032) compared to 100% wheat, 50% hulless barley and 75% hulless barley, respectively. 75% hulless barley reduced the postprandial GIP response by 2.8 nmol/L * 240 min (95% CI: 1.2, 4.5; P = 0.001) compared with 100% wheat.

The postprandial GLP-1 responses did not differ among the four test meals (P > 0.05).

FFA and TG responses

Changes in concentrations of FFA and TG as mean changes (± SEM) from baseline in percentage together with the postprandial responses as incremental area under curve (iAUC) are presented in Figure 2. The postprandial TG iAUC responses did not differ among the four test meals (P > 0.05). The postprandial FFA responses were suppressed after alle four diets, but more after 100% wheat compared to 50% hulless barley and 50% AmOn, by 19.0 mmol/L*240 min (95% CI: 1.3, 37.0; P = 0.036) and 20.8 mmol/L*240 min (95% CI: 3.0, 38.7; P = 0.023), respectively. No difference in postprandial FFA suppression was seen between wheat and 75% hulless barley (P = 0.566).

The present study evaluated acute effects of 50 g carbohydrate meals of different barley flour bread types on postprandial glucose metabolism in subjects with T2D compared to 100% wheat flour bread.

Our major finding was that by replacing 50% of the wheat flour with 50% AmOn, postprandial glucose responses were reduced by 34%, 27%, 23% (P < 0.05) compared with 100% wheat flour bread, 50% hulless barley flour bread or 75% hulless barley flour bread, respectively. Furthermore, by replacing 75% of wheat flour by hulless barley the postprandial glucose response was reduced by 11% compared to 100% wheat flour bread. In addition, the postprandial insulin response after 50% AmOn bread was lower than after 100% wheat bread and 50% hulless barley, indicating that the difference in glycaemic response was not caused by higher postprandial insulin levels. The postprandial insulin after 75% hulless barley was lower than to 50% hulless barley, but rather puzzling not to100% wheat. The differences in glucose responses may partially explain why glucagon is less suppressed after 50% AmOn and 75% hulless barley than after 100% wheat. Interestingly, GIP responses were lower for AmOn bread than the three other breads, probably due to the higher fibre content and lower glucose response to AmOn bread (26). Similar GLP-1 responses were detected to the four bread types. FFAs were suppressed after all four meal tests, however less after 50% AmOn and 50% hulless barley than after 100% wheat. The reduced suppression of FFA after 50% AmOn compared to 100% wheat might be related to the difference in insulin response between the two bread types; however, there were no observed difference in postprandial insulin between 50% hulless barley and 100% wheat. There was no difference in the postprandial response of TG between the four test meals.

Lowering the postprandial glycaemic responses in diabetes is important. Thus a diet low in GI and glycaemic load is optimal for prevention and management of T2D, cardiovascular diseases and mortality (5).

Even though the bread analyses showed similar content of carbohydrate in the four breads, the fibre content in 50% AmOn bread was 14%, 9% and 5% higher compared with 100% wheat, 50% or 75% hulless barley bread, respectively. In addition, the total fibre content was increased by 5% and 9% in 50% and 75% hulless barley bread compared with 100% wheat bread. The beneficial effects on postprandial glucose metabolism of AmOn and hulless barley bread compared to 100% wheat bread may partly be due to a higher fibre content. Thus, previous studies have found that glycaemic responses are strongly related to β-glucan content and that addition of β-glucan reduces GI in subjects with either T2D (7–9, 27). A high content of RS and fibres, as seen in the 50% AmOn, 50% hulless and 75% hulless barley bread, has previously been observed to decrease GIP and GLP-1 with mixed results on subjective satiety (28–30). We found that the GIP responses were reduced to 50% AmOn compared to all other three bread types and after 75% barley compared to 100% wheat being in line with previous studies in T2D where the acute GIP response was lower in T2D after a high fibre meal (26). In contrast; however, we did not observe any no differences in the postprandial response of GLP1 to the four bread types.

The observed glycaemic responses to AmOn with in vitro studies, where AmOn bread showed lower predicted glycaemic responses than regular barley (15). The same study found that the AmOn barley had a significant effect on composition and growth of gut microbiota in vitro.

The amount of RS in 50% AmOn flour bread of 55% was higher than in both 50% and 75% hulless barley and 100% wheat (RS 42%, 45% and 33%, respectively). Furthermore, the amount of RS was also increased after both 50% and 75% hulless bread as compared to 100% wheat. The higher amount of RS in combination with the higher fibre content may contribute to the positive impact on postprandial glucose metabolism. Previously, it has been demonstrated that also fasting plasma glucose is reduced after RS compared to digestible starch (31).

Our acute study does not add information on how mixing wheat flour with hulless barley or AmOn may influence weight or satiety. Previous human studies have reported mixed results on the effect on satiety after replacement of digestible starch with RS (29, 32). Interestingly, previous animal studies showed that hulless barley compared to wheat elicited lower body weight gain and improved insulin sensitivity (33).

The baking quality of barley flour is less than that of wheat flour. Bread volume and pore size in the crumb is dependent of the strength and elasticity of the protein gluten network formed by interconnecting disulphide bonds in the dough (34). This gluten network consists mostly of high molecular weight glutenin subunits (HMW-GS). In most wheat varieties the HMW-GSs are encoded by 4–5 different genes, whereas the barley genome only contains one gene homologous of the wheat HMW-GS, called D-hordein (35). This reduction in the level and/or diversity of glutenin subunits directly affects gluten strength and bread volume. Barley breads are generally more compact and regarded less attractive to consumers than wheat breads. Therefore, there is a need for improving breeding techniques and the use of baking additives e.g., enzymes or hydrocolloids to increase bread volume, crumb pore size and sensory attractiveness of barley breads further.

The single-blinded, randomised, cross-over design is a strength of our study. However, it has the limitation that using AmOn is not commercially an option in Denmark due a prohibition of genetic modified breads here. Consequently, we are developing AmOn barley-varieties according to publicly accepted protocols. By improving baking quality of hulless barley and increasing the amylose content it may have a future potential as functional food for prevention and management of T2D.

In conclusion, the present study shows that consuming bread made by replacing wheat flour by either 50% AmOn or 75% hulless barley lowers postprandial glucose in subjects with T2D. However, long-term studies with bread made by replacement of wheat flour bread with hulless barley and AmOn flour bread as part of the diet are requested to clarify effects on both diabetes regulation, body weight, lipid metabolism, satiety and gut microbiome.

Data Availability Statement

Data from the study can be found within the article and additional data are available from the corresponding author on reasonable request.

Acknowledgments

We thank the study participants for their contribution and time. We thank Eva Mølgaard Jensen and Lene Trudsø for their excellent laboratory technical assistance. We appreciate the statistician assistance from Morten Overgaard (Aarhus University, Denmark). We are grateful for the production of wheat and hulless barley bread by chief baker P.A. Andersen and his staff (P.A. Andersen Bakery, Vejle, Denmark). Thanks to Dagmara Podzimska-Sroka and Rikke Bækhus Jacobsen (Plantcarb Aps) for their contribution to the production of barley grain, barley flour and bread baking. We thank Andreas Blennow for valuable contribution on designing the research.

Author Contribution Statement

M. Bohl (MB), S. Gregersen (SG), K. H. Hebelstrup (KHH) and K. Hermansen (KH) designed research; MB conducted research; MB and Y. Zhong (YZ) analysed data; MB, SG, KHH, YZ and KH wrote the paper; MB had primary responsibility for final content. All authors read and approved the final manuscript.

Funding

Funding was provided by Innovation Fund Denmark (9067-00004A).

Competing Interests

KHH is co-owner of Plantcarb, which is a company that specializes in the production and application of high-amylose starches. The other authors declare no conflicts of interest.

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Table 1. Baseline characteristics of the 18 completing participants with type 2 diabetes (mean values ± SEMs; ranges in parentheses).

18 completing participants
Gender (female, n (%))	13 (72%)
Age (y)	60.5 ± 2.7 (38-75)
HbA1c (mmol/mol)	49.7 ± 1.1 (43-59)
BMI (kg/m2)	30.5 ± 1.1 (19-44.8)
Total cholesterol (mmol/L)	4.1 ± 0.1 (3.1-4.9)
LDL-cholesterol (mmol/L)	2.0 ± 0.1 (1.2-1.7)
HDL-cholesterol (mmol/L)	1.2 ± 0.1 (1.0-1.7)
Statin use n (%)	13 (72%)
Anti-hypertensive drugs n (%)	12 (67%)
Metformin n (%)	15 (83%)
Other oral antidiabetics n (%)	5 (28%)
Smoking n (%)	3 (17%)

Abbreviations: HbA1c, haemoglobin A1c; BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein.

Table 2. The moisture, total fiber content, total starch content and starch digestibility of bread samples(mean values ± SD with three replicates).

Bread types	Moisture content (%, wet basis)	Total carbohydrate (%, dry weight)	Total fiber content (%, dry basis)	Total starch (TS) content (%, dry basis)	Rapidly digested starch (RDS) (%)	Slowly digested starch (SDS) (%)	Resistance starch (RS) (%)
Wheat	44±4^a	77±1^a	8±0^d	69±1^a	26±4^a	41±3^a	33±2^c
50% hulless barley	41±2^a	78±1^a	13±1^c	64±1^b	29±8^a	29±1^b	42±5^b
75% hulless barley	45±0^a	77±0^a	17±1^b	61±1^c	15±2^b	40±7^a	45±2^b
50% AmOn	41±6^a	76±1^a	22±1^a	54±2^d	26±6^a	19±3^c	55±2^a

Values with different letters in the same column are significantly different at P < 0.05. Starch fractions were classified as rapidly digested starch (RDS), slowly digested starch (SDS), and resistant starch (RS).

There is NO conflict of interest to disclose.

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Beneficial glycaemic effects of barley bread compared to wheat bread in type 2 diabetes

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Abstract

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Introduction

Subjects And Methods

Study design

Study participants

Production of dietary supplements and dietary assessment

Bread component analysis

Visits

Blood analyses:

Statistical analysis:

Results

Baseline clinical characteristics

Bread fibre and starch content

Plasma glucose, insulin and glucagon responses

GIP and GLP-1 responses

FFA and TG responses

Discussion

Declarations

References

Tables

Additional Declarations

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