The best option is to breastfeed the baby exclusively and try to improve the milk produce by adopting measures like plenty of fluids , avoidance of stress, increasing night time feeds,ensuring proper attachment and latching. The next best option would be to express the breast milk and feed using katori spoon with proper sanitation If milk production appears inadequate as reflected in poor weight gain, excessive cry and less urine frequency u can use age appropriate formula feed using katori and spoon As far as pros of bottle feeding is concerned there is none Its just going to introduce hell lot of gut infections leading to diarrhea and dysentery no matter how well u clean those bottles and also it would cause nipple confusion leading to improper breast suckling furthermore. Bottomline : a big no to bottle feeding

Better to use paladai or katori spoon that are easier to clean and improve baby's sucking swallowing

Try to exclusively breastfeed your baby . Breast milk is wholesome and complete . Try all measures to increase breast milk eg increase your fluid intake ,be relaxed ,try back massage.

Consult to Pediatrician physically for further evaluation and treatment