3D bioprinting capsules of probiotic bacteria

In a recent article published in the magazine Health food hydrocolloidsIn this article, the researchers discussed an efficient and reliable method for making capsules carrying probiotic bacteria using 3D bioprinting.

Stady: An easy and powerful method for preparing capsules to deliver probiotic bacteria by 3D bioprinting. Image Credit: FOTOGRIN / Shutterstock.com


Several studies have shown that changes in the microbiota can cause autoimmune diseases, allergies, inflammatory disorders, and diseases including obesity and diabetes, among others. Therefore consumption of probiotic bacteria is essential to maintain a healthy and functional microbiota environment, and the metabolic activity of probiotic bacteria is what makes the normal intestinal microbiota better.

One of the most common and clinically studied probiotic bacteria is Lactobacillus rhamnosus GG (LGG), which has been shown to have advantages in modulating immunity and digestive health. A large part of the bacteria cannot withstand the difficult conditions of the upper digestive tract. The gastrointestinal environment, which prevents LGG from reaching the surface of the intestine and acting as a recovery agent, thus limits the efficacy of the activity of probiotics.

In this regard, several strategies have been developed for the encapsulation of microorganisms in the food industry. The viability of probiotics is one of the main problems in their formulation because it decreases after processing or during storage. To protect bacteria during processing steps, several techniques have been developed to encapsulate bacterial cells. An approach that is frequently used and used in many different areas of research is bioprinting using mammalian cells and hydrogels. However, there are very few reports on the printing of bacterial cells in three dimensions. While 3D bioprinting of bacterial cells has been documented in some cases, 3D bioprinting techniques have never been used to preserve the health-promoting properties of bacteria.

About the study

In this study, the authors discuss a sophisticated microextrusion method for 3D bioprinting of probiotic bacterial capsules. Encapsulated LGG bacteria that were stable for 7 days were printed using a mixture of gelatinous gel, sodium alginate, and LGG as a bio-ring. The proposed technique for creating microorganisms in capsules was quick and easy. Within 30 minutes, 120 probiotic capsules were printed with 108 CFU/ml. The encapsulated LGG bacteria were uniformly dispersed throughout the alginate-gelatin hydrogel upon microscopic analysis of the LGG capsules. The bacteria in the capsules have resisted the difficult gastrointestinal fluid environment in the laboratory They were kept alive and viable for 7 days at 4°C.

The team used a comprehensive encapsulation process using 3D bioprinting technology to address the inconsistency and ineffectiveness of current encapsulation techniques to target probiotic bacteria for the oral small intestine. A direct 3D bioprinting method for micro-extrusion has been developed to encapsulate probiotic bacteria for oral administration. This study used a 3D bioprinter to create capsules containing probiotic bacteria Lactobacillus rhamnosus G.G.

The researchers used standard microbiology techniques, scanning electron microscopy (SEM), confocal microscopy, infrared spectroscopy, and atomic force microscopy (AFM) to analyze the properties of the LGG capsules. For LGG capsules that were 0, 2 and 7 days old, development and viability of the matrix-coated probiotics were observed in agreement with the minimal amount. To observe how LGG capsules behave once they reach the intestinal target, I was eventually exposed to digestive fluids in the in the laboratory digestion system.


After passing through gastrointestinal simulating fluids, the log CFU/ml for LGG capsules was 8.1 compared to 7.9 in the absence of the in vitro digestion stage. After passing through GI fluids, the log CFU/ml for the uncoated capsules containing probiotic and free bacteria was 7.5 and 7.4, respectively. The log CFU/ml was 9.3 and 9.1 in the absence of GI fluid, indicating a 30-fold decrease. After adding WST reagent 1 on days 0, 2, and 7 to LGG capsules, the absorbance at 460 nm was found to be enhanced by 2.7, 2.8 and 3.3-fold compared to the medium alone, respectively.

After loading with LGG bacteria, gel hardness marginally increased from 3.1 to 3.6 kPa. Mechanical breakdown was seen after 7 days, as indicated by the pressure drop from 3.6 to 1.1 kPa. Black features appeared after bacteria were absorbed into the polymer matrix, indicating that LGG cells were evenly distributed throughout the bioprinted 3D film. The capsules were kept stable at 4°, 23° and 37° C. The capsules were also stable in water and PBS, but when sodium citrate was added, they rapidly disintegrated at 37 °C for 30 min.


In conclusion, this study used a 3D biological printer and sodium alginate as a packaging medium to devise a new method for encapsulation of probiotic bacteria. Within 30 minutes, 120 LGG capsules were produced, each carrying 8 log CFU/ml LGG. The gelatinous gelatin matrix of LGG capsules contained evenly distributed microorganisms. LGG inside the capsules was working. The probiotic bacteria inside the capsule survived in a demanding gastrointestinal fluid environment created in in the laboratory Digestion preparation.

The authors stated that the proposed bioprinting technology would make it possible to quickly and simply create encapsulated bacteria, which would dramatically change the food sectors. They also stated that this bioprinting technique for encapsulating probiotic bacteria for their precise delivery into the stomach could be a game-changing approach for commercial use.

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Malik, A, Quills, F, Francis, C, et al. An easy and powerful way to prepare capsules for the delivery of probiotic bacteria by 3D bioprinting. nutritional water colloids for health, 100088 (2022). https://www.sciencedirect.com/science/article/pii/S2667025922000358.

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