While GMP provides flexibility to use additives “as required for the intended purpose,” it lacks quantifiable control. Without defined limits, there is a risk of overuse, which can compromise product safety and efficacy. Excessive stabilizer or emulsifier usage could impact:
- Gut health: Overuse of additives like carboxymethyl cellulose or polysorbates has been linked to gut microbiota disruption.
- Safety: Long-term or excessive consumption may lead to bioaccumulation and potential toxicity risks.
For Example, Natural emulsifiers, such as lecithin (phosphatidylcholine), are broken down in the small intestine by intestinal lipases into choline-rich nutrients, which are then metabolized by bacteria to produce triethylamine (Szuhaj, 1989; JECFA, 1974a). In contrast, synthetic emulsifiers exhibit greater resistance to digestive breakdown. For instance, polysorbate 80 undergoes partial digestion, where its fatty acid components are effectively metabolized, but the sorbitol portion remains highly resistant to intestinal digestion (JECFA, 1974b; Singh et al., 2009). Similarly, carboxymethylcellulose, a non-digestible polysaccharide polymer, is widely used as a thickening agent and stabilizer in food emulsions due to its indigestibility (Halmos et al., 2019). Citric acid esters of mono- and diglycerides, commonly used to stabilize food emulsions and infant formulas, were previously believed to undergo complete hydrolysis in the gut, yielding free fatty acids, glycerol, and citric acid. However, recent evidence suggests that the ester bond between citric acid and glycerol may not be fully hydrolyzed (Amara et al., 2014).
The following Table sheds light on impact of additives on microbiota and host physiology.
| Type of Additive | Additive and Dose | Model | Effect on Microbiota | Effect on Host Physiology | Reference |
| Colour | Titanium dioxide (2.3 x 10⁵–2.3 x 10⁹ particles/ml) | Human colon cells | Not determined | Decrease in absorptive microvilli, decreased nutrient uptake | Guo et al. (2017) |
| Emulsifier | Carboxymethylcellulose (2% w/v within drinking water for 3 weeks) | Mice (Il10−/−) | Bacterial overgrowth | Intestinal (small bowel) inflammation | Swidsinski et al. (2009) |
| Emulsifier | Carboxymethylcellulose, Polysorbate 80 (0.1 to 1% v/v within drinking water, 12 weeks) | Mice (Il10−/−, Tlr5−/− & C57BL/6) | Microbiota encroachment, altered species composition | Colitis, metabolic syndrome | Chassaing et al. (2015) |
| Emulsifier | Carboxymethylcellulose, Polysorbate 80 (0.1 to 1% v/v faecal suspension culture) | M-SHIME human colon model | Not determined | Increased levels of bioactive flagellin (pro-inflammatory potential) | Chassaing et al. (2017) |
| Emulsifier | Polysorbate 80 (1% v/v per kg bodyweight via gavage, daily for 4 weeks) | Mice (C57BL/6) | Altered microbiota composition | Intestinal inflammation, obesity, impaired glycaemic tolerance, liver dysfunction | Singh et al. (2016) |
| Emulsifier | Polysorbate 80 (1% w/v in drinking water for 8 weeks) | Mice (C57BL/6J) | Altered microbiota composition | Enhanced indomethacin-induced intestinal damage | Furuhashi et al. (2019) |
| Emulsifier | Glycerol monolaurate (150 mg/kg ingested daily for 8 weeks) | Mice (C57BL/6) | Altered microbiota composition | Metabolic syndrome, systemic low-grade inflammation | Jiang et al. (2018) |
| Emulsifier | Methylcellulose (150 g/kg in chow for 7 days) | Mice (Rag1-/- & C57BL/6J) | Not determined | Increased severity of colitis | Llewellyn et al. (2018) |
| Preservative | Silver nanoparticles (0, 11.4, 114, 1140 μg Ag NP/kg bodyweight/day for 28 days) | Mice (C57BL/6) | Altered microbiota composition | Not determined | Van Den Brûle et al. (2016) |
| Sweetener | Sucralose (100, 300, 500, or 1000 mg/kg/day for 12 weeks via oral gavage) | Rats (Sprague Dawley) | Altered microbiota composition | Not determined | Abou-Donia et al. (2008) |
| Sweetener | Sucralose (0.1 mg/ml within drinking water for 6 months) | Mice (C57BL/6J) | Altered microbiota composition | Altered bile acids, elevated pro-inflammatory gene expression in liver | Bian et al. (2017b) |
| Sweetener | Sucralose (1.08, 3.5, 35 mg/ml within drinking water for 6 weeks) | Mice (SAMP, AKR, and C57BL/6J) | Altered microbiota composition | Increased ileal tissue myeloperoxidase activity | Rodriguez-Palacios et al. (2018) |
| Sweetener | Saccharin (0.1 mg/ml within drinking water for 5 weeks) | Mice (C57BL/6) and humans | Altered microbiota composition (mice only, humans not studied) | Glucose intolerance ( | Bian et al. (2017c) |
| Sweetener | Aspartame (5–7 mg/kg/day for 10 weeks) | Rats (WT) | Altered microbiota composition | Glucose intolerance | Palmnäs et al. (2014) |
| Sweetener | Acesulfame K (37.5 mg/kg/day for 4 weeks) | Mice (CD-1) | Altered microbiota composition | Weight gain (male mice only) | Bian et al. (2017a) |
| Thickener | Maltodextrin (1 to 5% w/v within drinking water over a period of 45 days) | Mice (Balb/c) | No effect on microbiota composition | Altered mucus barrier, increased intestinal inflammation | Laudisi et al. (2019) |
By adhering to a specific limit, we ensure that the product remains safe, consistent, and aligned with regulatory practices.
References:
Elliott, C., Keast, R. and Cicerale, S., 2020. The influence of bitter-tasting components in food on satiation and satiety. Nutrition Bulletin, [online] 45(1), pp.39–52. Available at: https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12408 [Accessed 27 Apr. 2024].
Abdallah, A., 2023. Food additives: Assessing the impact of exposure to permitted emulsifiers on health. Elsevier Pure, [online] Available at: